Stephen Baxter’s "Ark"

A detailed plot summary


By Stephen Baxter
London: Gollancz, 2009
457 pp.


Part One: August 2041

Chapters 1-3

In August 2041, Lily Brooke engineers a trade - Nathan Lammockson gives “Project Nimrod” (Ark One’s codename) his Norwegian seed cache in exchange for the possibility of a place on Ark One for Grace Gray, who is pregnant by her husband Hammond – Nathan’s son.

Grace arrives at the Ark One project’s base in Alma, Colorado (chosen for its position as the highest town in the U.S.), where she meets another Ark One Candidate, Holle Groundwater, and learns that the Ark is an interstellar spaceship. To prove her abilities, Grace is asked to solve a crime – the murder of a man named Harry Smith.


Part Two: 2025-2041


June 2025 (Chapters 4-10)

Holle Groundwater – aged six – and her father Patrick arrive in Denver, the new U.S. capital following the loss of Washington, D.C. and much of the country’s low-lying states. With the sea-level rise at 200 metres, Patrick has come to a meeting of LaRei – a club for the super-rich working on the Arks and other survival projects. At the meeting, scientist Thandie Jones asserts that there will be no end to the sea-level rise and they now have only 15 years before Denver is flooded.

Afterwards, Patrick is invited to a briefing about one of the Ark projects – a project that aims to leave Earth altogether. One option - settling within the Solar System in space stations, on Mars or the outer moons, or on the asteroids - is rejected due to the poor results achieved in long-term closed life support systems on the ISS and other space projects. The other option is travel to another Earth-like planet, the nearest believed to be 16 light-years away – too far for any conventional propulsion system. Scientist Liu Zheng considers Faster-Than-Light (FTL) travel necessary and suggests the use of an Alcubierre Drive.

Harry Smith, a teacher, is at the meeting to look after the children and seems to display too great an interest in them.


January 2031 (Chapters 11-13)

Holle enters “The Academy” in Denver where both Liu Zheng and Harry Smith are instructors for the children of LaRei club members selected as Candidates. Holle learns that Gunnison, Colorado, has been chosen as the launch centre.

Attending a lecture by Liu Zheng with Candidate Zane Glemp, Holle helps Liu arrive at a possible solution to the seemingly insurmountable energy requirements of the Alcubierre Drive - a “sub-neutrino-sized corridor to a pocket universe containing a spaceship”. He states that factors normally associated with FTL travel - such as time dilation - don’t apply as the ship itself is not moving within the warp bubble.

We also meet Venus Jenning, another Candidate.


May 2032 (Chapters 14-17)

The current plan is to use Ares I and Ares V boosters over the next eight years to launch Ark One modules to the ISS which is to be refurbished and used as a construction shack. Antimatter for the Alcubierre Drive is being manufactured at a facility near Denver.

It has been decided to exclude anyone with strong religious views – including atheists – from the Ark, in an attempt to prevent factionalism. Many talented Candidates are lost as a result.

U.S. President Vasquez announces a government takeover of the Ark project which is to be placed under Air Force control, as it becomes clear that the flood is not going to stop and the project is chaotic, poorly managed and well behind schedule: “Your starship must be ready to fly by 2040, or all our futures may be lost.”

Former astronaut Gordo Alonzo completely overhauls the project, renaming it Nimrod (from Genesis 11:6, “...and now nothing will be restrained from them, which they have imagined to do”), replacing all the ethics and sociological classes with practical training, and ejecting (sometimes completely randomly) LaRei Candidates in favour of outsiders.


September 2036 (Chapters 18-23)

One of the main technical problems facing the Ark’s designers is the apparently impossibly large amounts of energy required to create a warp bubble. They realise however that it is not the bubble itself that requires energy – only the connection between the universe and the bubble – which can be miniscule.

The crew size will be 80 – all young adults to give them the best chance of finding partners the same age.

However, enormous problems continue – and it becomes clear that the schedule is simply impossible to achieve in its present form by 2040. Further compounding these problems, the antimatter facility is destroyed in an accident which exposes safety and other shortcuts.

The solutions arrived at are:

Firstly, as they can’t make antimatter they will mine it: the flux tube between Io and Jupiter is a natural particle accelerator. The Ark will fly to a remote orbit around Jupiter, (to avoid its dangerous radiation) and use an unmanned ramjet spacecraft to collect antimatter there.

Secondly, as it is clearly impossible to launch enough conventional boosters in time, Liu Zheng suggests using an Orion nuclear pulse propulsion vehicle. The Alcubierre Drive will still be used for the FTL interstellar journey to Earth II, with an Orion craft taking them from Earth to Jupiter before being re-assembled for the interstellar journey once enough antimatter is collected.


December 2038 (Chapters 24-26)

The flood reaches 1,200 metres, affecting Colorado itself. The mission to Earth II will take eight years altogether. The latest plan is to include women in early pregnancy.


September 2039 (Chapters 27-30)

During an extremely chaotic evacuation of the Candidates along with the rest of Denver, Holle becomes separated and is attacked by “IDs” (or eye-dees - Internally Displaced refugees) for her clothing. Unable to convince anyone of her real identity, she is drafted into forced labour as Denver is mined to stop further waves of refugees following. She is finally rescued by Candidate leader Kelly Kenzie, who informs her that a test of the warp drive on an Ares booster was successful.

They travel to the launch centre at Gunnison. Mission control is at Alma.


August 2041 (Chapters 31-34)

Catching up with events at the start of the novel, Grace interviews Candidates Zane Glemp, Venus Jenning, and Matt Weiss over Harry Smith’s murder, correctly deducing that Matt was guilty and proving her skills to Alonzo, who promises her a place on the Ark.

Harry Smith had been sexually abusing the three Candidates for several years - though Matt seemed to genuinely believe that he loved Harry.

The Orion is 30 metres wide and 90 high; the pusher plate is 40 metres across and 10 cm thick. The craft’s total weight is 4,000 tonnes, with a 1,000 tonne payload. The nuclear pulse units have a 5 kt yield.


November 2041 (Chapters 35-39)

As the outside situation becomes increasingly hopeless, the final selection of 80 crew members takes place. Only about 60 are from the Candidates, the rest going to “Gatecrashers” - the children of politicians and military commanders, a concession Gordo Alonzo states he had to make to ensure their loyalty in the final days before launch. President Peery, addressing the final crew, reveals the existence of Ark Two, a sanctuary on Earth, a parallel and equally secretive project.

Such is the chaos and unreadiness of the craft, Holle is asked to help convince Matt Weiss, held prisoner after confessing to Harry Smith’s murder, to be part of a suicide squad who will remain at the launch site to fix coolant leaks and numerous other problems in the final minutes before launch.


December 2041 (Chapters 40-45)

The launch is brought forward twelve hours when it becomes clear that the perimeter cannot be held until the planned launch time. Matt finishes fixing a coolant leak seconds before launch. Amidst heavy fighting on the perimeter, some ground crew and guards mutiny and get on board. Despite this, Ark One launches successfully, creating a crater kilometres wide and obliterating the launch centre, technicians, troops and insurgents. Liu Zheng supervises the suicide squad, standing directly beneath the pusher plate as the first bomb ignites.



Part Three: 2042-2044

February 2042 (Chapters 46-48)

It is 40 days after launch. The Ark has travelled 90 million km – one-tenth the way to Jupiter. It is travelling at 26km/sec, 58,000mph – twice the speed of the Apollo spacecraft. There will be a one year voyage to Jupiter under weightless conditions. Mission control will continue from Alma for two years until FTL warp begins and contact is lost.

At a ship’s council a crew census report is given. There are 78 on board (two less than planned): 49 ex-Candidates, 21 late additions approved by Alonzo - the Gatecrashers, and eight “illegals” - from the last-minute mutiny among the guards and technicians before launch. The illegals are loosely led by Masayo Saito, who claims – with some justification – to have simply been swept on board unintentionally during the panic.

The illegals also include the Shaughnessy brothers Jack and Paul, Jeb Holden and Dan Xavi. Only one of the three doctors intended for the crew – Wetherbee – made it on board.

The ship has two connected crew hulls, eight metres in diameter and 50 long, giving 4,700 cubic metres living space including storage areas.

Captain Kelly Kenzie orders Holle to mount a raid to remove the weapons she believes the illegals brought aboard. Grace goes into labour.


June 2043 (Chapters 49-51)

There are now three infants onboard ship, which has been in a distant orbit of Jupiter for seven months. Venus Holling leads a planetary survey: Due to the ship’s limited lifespan, a maximum seven year cruise at three times light speed giving a maximum distance of 21 ly has been set. There are 70 star systems in range, but only five Sol-like G-class stars. There is a debate over whether to target systems with G-class stars or Earth-like planets – there are none with both.

While the antimatter is gathered by an unmanned craft, the vessel is reconfigured for the interstellar warp flight. The two crew hulls have been separated, necessitating EVAs to get from one to the other. The two hulls will be tethered with the warp generator – a compact collider ring – in the middle and spun around each other inside the warp bubble for artificial gravity.


March 2044 (Chapters 52-56)

Back on Earth in Alma, Colorado, Mel is on patrol. The flood has reached nearly 3,000 metres. The Ark is due to warp in 24 hours, and Mel and Don, along with the other troops in what is rumoured to be the last surviving area of federal control, are tasked with keeping mission control safe until then. One tactic involves tricking IDs to enter a “respite centre” where they are killed by poison gas.

The target has been decided on – 21 ly to 82 Eridani in the Eridanus (“River”) constellation.

A coordinated attack on mission control begins. The warp jump has already begun, but staff want to wait for the signal to arrive at Earth. IDs overrun the defenders and with computers failing mission control is evacuated. The President has ordered Gordo Alonzo, Patrick Groundwater, Thandie Jones and Kelly’s father Edward Kenzie be evacuated in the last operating helicopter to the New Jersey submarine, and perhaps then to Ark Two. Patrick gives up his place to Mel.

The warp initiation has been deliberately timed to coordinate with a lunar eclipse. On her raft, Lily Brooke sees the flare as the warp drive engages – the final event in the previous novel “Flood”.


Part Four: 2044-2052


September 2044 (Chapters 57-59)

The warp was activated on 13 March 2044. By September Ark Two is approaching the outer limit of the Oort Cloud. Their target is 82 Eridani in the constellation Eridanus.

There is a special parliament to mark six months of the warp voyage. The crew discuss how to organise society on the ship. Holle asks Zane Glemp, the ship’s only warp engineer, to be her partner, but quickly realises that Zane is mentally disturbed.


December 2046 (Chapters 60-63)

One of the problems facing the crew is the gender imbalance caused by the last-minute changes – with too many men, women will need to have a second child with another man besides their chosen partner for genetic diversity.

Doc Wetherbee believes Zane is suffering from dissociative identity (multiple personality) disorder, due to the abuse inflicted by Harry Smith.

Cora Robles’ daughter Meg dies in an accident, the first death on the voyage.


May 2048 (Chapter 64)

There is a serious fire in one of the crew hulls. It is cut from its tether to restore weightlessness, stopping the fire’s convection updraft and bringing it under control.


June 2048 (Chapters 65-66)

Thomas Windrup is sentenced for causing the fire, which resulted from his attempt to sabotage Jack Shaughnessy’s suit. He survived but four others died. Kelly has Thomas’ foot amputated as punishment. Wilson and Venus challenge her and she steps down. The three stand as Candidates for Speaker for an election in one week.

Wetherbee hypnotises Zane and discovers at least two - and probably more - separate identities.


July 2048 (Chapter 67)

Wilson wins the election.


September 2049 (Chapters 68-69)

Venus shows Holle the first images of the target planet. Earth II is orbiting 82 Eridani but tipped over on a 90 degree axial tilt – like Uranus – each hemisphere experiences constant light for one half of a year and darkness the other.

Venus says she has found no signs of intelligent life anywhere in the galaxy.


December 2051 (Chapters 70-72)

Venus gives the crew a report on Earth II which the Ark has now been orbiting for six months. There seems to be plant life on the day side, but snow hundreds of metres deep on the night side. It is slightly smaller than Earth with 0.8 g gravity. The air should be breathable with a face mask. Earth II is much less geologically active than Earth and thus can’t sustain as much life. It is older than Earth – one billion years ago it would have been much more Earth-like.

Observations show evidence of an extinct civilisation: there are no oil or minerals near the surface and the system has few asteroids - suggesting that the planet and then the system’s resources were used up. The worst problem is the planet’s obliquity – Venus argues that humans can’t survive the massive seasonal swings – they have to go on to another destination.

She suggests a more habitable “Earth III” in the constellation Lepus in Orion – 90 ly or 30 more years’ voyage away. Kelly however argues that if Earth II is harder to survive on than Earth they should go back home.

Three groups emerge: Those who wish to settle on Earth II, those who want to return home to Earth, and those who want to continue on to Earth III.

Zane points out that with two crew hulls, four shuttles, and the ability to split the warp generator in two, it is technically feasible to split the ship into parts to allow all three options.

But it seems that the future of mankind is being decided by the fact that after a decade on Ark One they are all sick of each other.

November 2052 (Chapter 73)

A year later the Ark has been successfully reconfigured. The warp generator is now rebuilt as two copies of itself and the two hulls separated, which also returns them to weightlessness for the rest of their separate journeys. One of the four shuttles takes the Earth II group - about 15 adults - down to the planet’s surface (this is the last we hear of them in the novel). As its journey back to Earth will be the shorter of the two, the second group of about 19 adults take the fire-damaged hull and one shuttle back to Earth. Finally, the undamaged hull and two shuttles set out for Earth III with about 40 adults led by Wilson, who discovers that Kelly has kidnapped Doc Wetherby to return to Earth.


Part Five: 2059


July 2059 (Chapters 74-79)

On Thandie’s raft, Boris sees the Ark section arrive in Earth orbit. Thandie orders a radio beacon out to guide it home.

The 19 adults and four children born on the voyage home make Earth observations from orbit. The flood is “only” 15km above the old sea level - rather than the 25km expected. There is no exposed land left anywhere. Earth’s weather is much simpler with no land to interfere with weather systems: “The Spot” - a vast storm system similar to Jupiter’s Great Red Spot - with winds of 300km/h, is still in existence, spinning off daughter storms. The crew pick up Thandie’s message from the “Panthalassa Sea” over Wyoming.

The Ark’s shuttle lands on the ocean near Thandie’s raft. Earth’s air is thicker with the oxygen levels down to about 16 percent. The flood is finally tailing off and is expected to stop at about 18km above the former sea level and five times its former volume. The planet’s heating may continue until it is too hot for humans to survive.

The few surviving raft communities mostly stay over the sites of former cities to collect the garbage that still floats up from them. Kelly tells Thandie she wants to contact Ark Two, which Thandie says is located at the former site of Yellowstone National Park.

On the other Ark hull, which is now weightless again en route to Earth III, Theo and Holle attempt unsuccessfully to integrate Zane’s multiple personalities.

The younger generation on Ark One are increasingly influenced by Zane, who tells them that they are really in a simulator on Earth, not on an interstellar ship. Meanwhile, Holle, Venus and Grace confront Wilson over his relationships with the ship’s young girls. Wilson responds that sex is the only privilege that power can bring him on the ship, a rule enforced by his “illegals” henchmen.


August 2059 (Chapters 80-82)

A sub from Ark Two arrives at Thandie’s raft. A young crew member - Dexter - Kelly’s son abandoned by her in 2041 to join the mission - has read the ship’s logs and says he and the other Ark Two members regard the Ark One crew as heroes. Ark Two is a series of habitats on the seabed 12km down, over what used to be Yellowstone. It has 100 inhabitants including 30 under 18 years old. They live off fish and the black smoker ecologies, extracting geothermal power from the ground below.

Ark Two was built in the 2020s on what was then dry land. As it was covered by the rising sea level in 2043 IDs attacked it constantly and managed to destroy one dome - killing Gordo Alonzo. But with a rise of 300 metres a year it quickly became too deep to attack.

They visit Edward Kenzie, Kelly’s now 95-year-old father, who accuses her of failure for returning to Earth.

Part Six: 2068-2081

May 2068 (Chapter 83)

Ship-born young woman Steel (Wilson’s former child sex slave), and Max, whose twin sister Terese is Wilson’s current slave, steal explosives to use against Wilson.


June 2068 (Chapters 84-89)

There is an uprising of ship-born led by Steel, who has one of the guns confiscated from the illegals at the beginning of the voyage. They believe they are really in a simulator on Earth. Wilson lives in the “bridge” - the nose of the hull with Theo, his four other “illegals” henchmen and child sex slaves.

The ship’s children are split into various tribes.

Wilson escapes to one of the two shuttles with Terese before the children use the explosives to break through to the bridge. The children intend opening the hull to “expose the lie”. Grace, Holle and Helen get as many people as possible into the cupola and second shuttle. Wilson’s shuttle has been sabotaged; however he escapes in a suit while the shuttle is destroyed when it reaches the warp bubble’s boundary, killing Terese. At least one of Wilson’s henchmen is killed by the children in retaliation for the years of sexual abuse suffered at his hands.

After the hull breach, 40 crew survive in the shuttle and 20 in the cupola, many with varying degrees of injury. Holle now takes control, allowing Wilson to live due to his essential skills. Steel is executed. Holle institutes a “tough love” regime - they cannot allow young hotheads like Steel to threaten the mission for its remaining decade - or allow the abuse of power that led to it either. She institutes a regime of surveillance and control from the centre - for now, the only right is the chance to survive the journey.


May 2078 (Chapters 90-92)

As part of Holle’s policies, many children have been born since 2068, though a moratorium is now in place up till landing to avoid having young children during planetfall.

Venus theorises that the reason for not detecting evidence of intelligent life lies in the fact that the galaxy is old - Earth was a latecomer, and any civilisations have migrated to the galactic core where there is greater star energy available.


February 2079 (Chapter 93)

Venus once hears a radio signal she believes could be from a non-natural source. She never hears it again and tells no one.


July 2081 (Chapters 94-95)

In orbit around Earth III, Venus gives a report on the planet.

Earth III is a super-Earth orbiting a red dwarf star in the constellation Lepus, a star similar to Proxima Centauri. It is an M6 class star 111 light-years from Earth, twice Proxima’s mass and one-fifth of the sun’s. The day is as long as the year, leaving one hemisphere in constant light and the other in constant darkness. Despite being the closest in the system to its star, even the warmest areas of Earth III are icy. The planets further out are not as inhabitable but should be possible to colonise later.

It is a geologically active world and the atmosphere is very thick due to greenhouse gases from volcanic eruptions.

The climate is very different to Earth’s but stable. Instead of north to south climate zones, the sub-solar point is the warmest with visible concentric circles of climate zones and differing vegetation spreading out from there.

It has twice Earth’s mass and 25 percent higher gravity. Venus believes that the planet is ideal for their needs. However, only one shuttle out of four remains - its capacity of 25 people can be raised to 40 with internal refitting, but to save weight and take the largest possible number, Holle decides to send only three adults and 37 children aged 2-15 years, with most under 10 for weight advantages.


August 2081 (Chapters 96-98)

The shuttle leaves the Ark. Holle has chosen Wilson (as the only trained shuttle pilot), Grace’s daughter Helen, and Jeb, one of the illegals, as adult crew members. The remaining crew on the Ark plan to survey the planetary system using small warp jumps.

The shuttle lands safely on an ice-covered lake. As the youngest child crawls onto the planet’s surface, they see the Ark pass overhead and then blink out as it goes to warp.