Christa Justus and Mark Linn-Baker

Consider the actor Mark Linn-Baker, who played the straight man to Peter O’Toole in the 1982 comedy “My Favorite Year.” It was also the role he played against Bronson Pinchot in the late-’80s ABC sitcom “Perfect Strangers,” and in the 2003 Broadway musical “A Year With Frog and Toad.”

But in the fall of 2009, as a divorcing middle-aged father of an 8-year-old daughter, “I thought I was past a serious romantic relationship,” said Mr. Linn-Baker, now 58. “I was a single dad in New York City, raising a child and pursuing a career,” he said on a blustery December morning in a restaurant in the shadow of the George Washington Bridge. “Honestly, I didn’t think that would be particularly attractive to someone.”

So he asked his friends Kate Reinders and Jessica-Snow Wilson if they knew anyone he might go out with — someone appropriate and available, with whom a relationship was a real possibility.

On the surface, Christa Justus might not have seemed an obvious choice. An actress who works full time as the director of grants and operations for Gabrielle’s Angel Foundation for Cancer Research, she, too, had made choices that had left her alone. In 2004, her chances for marriage and children seemed to be dwindling, so she “grabbed the wrong person and moved to New Jersey,” she said. Four years later, still single, “I came screaming back across the G.W.B.”

But Ms. Wilson had a sudden epiphany.

“I said, ‘Oh, my God — Christa!’ and Kate said, ‘Who’s Christa?’ ” Ms. Wilson recalled. “And I said, ‘I think she’s his wife.’ ”

“The second I thought of it, I broke out in chills,” Ms. Wilson continued. “I said, ‘Who would get Mark, his intelligence, his sense of humor, the fact that he’s a dad? Who would think he’s the sexiest, awesomest guy alive?’ And she popped into my head. She’s one of my closest friends, and I wanted someone who would treat her like a princess. She exudes light, and she sees the beauty in people and in life. Mark is like her male counterpart.”

Ms. Wilson called her friend and said: “I know you like cute dads. Would you go out with Mark Linn-Baker?”

Ms. Justus, now 48, agreed to a blind date.

Over dinner, the two marveled at how many people they knew in common and how close their paths had come to crossing. Ms. Justus had been an understudy for Caitlin Clarke, a friend of Mr. Linn-Baker from Yale, in “Titanic” on Broadway. In the early ’90s, Ms. Justus and Mr. Linn-Baker had worked in Los Angeles at the same time. Later, they had worked for a year in Broadway theaters whose stage doors were near each other: he was in Neil Simon’s “Laughter on the 23rd Floor” at the Richard Rodgers and she was in “Les Misérables” at the Imperial.

Yet they had never met.

“In fact, Christa had missed my entire career, which I had thought was somewhat substantial,” he said with a laugh.

At the end of the evening, Mr. Linn-Baker pronounced himself very intrigued. Ms. Justus liked him as well but was reluctant to enter into another relationship.

“I made it very clear that I was not one to be pinned down,” she said.

He wasn’t buying it.

“Christa had a very hard exterior that never fooled me,” he said. “They say the two hardest things in this life are knowing what you want and being able to say it out loud.”

Almost immediately he knew what he wanted. And so he pursued her.

They met once a week until “I reached a point where I thought, once a week is not enough,” he said. “I’d like to see this person two times a week. But my big fear was, ‘Oh, my God, what if she wants a third night?’ ”

“Which I did not want,” Ms. Justus said.

Although they were not dating exclusively, Ms. Justus found herself drawn to Mr. Linn-Baker’s old-fashioned gestures, like the way he walked her home during a downpour but did not try to wheedle his way into her apartment, as other men had. When she told him early on that the only things she needed were a piano and a robe, he brought her a robe on their third date. Another time, after a discussion of dreams, he presented her with a book of symbols.

A couple of weeks before her birthday, “he sent a Trojan horse into my apartment,” Ms. Justus said of the huge box, wrapped in shiny purple paper, that she finally ripped open after the clock struck midnight on Feb. 26. It was a turntable.

“She had a huge collection of vinyl and nothing to play it on,” Mr. Linn-Baker said. “Here was somebody who loves music and was surrounded by music and couldn’t listen to it.”

“For me, it was a very moving moment,” she said. “Mark always bought me the most thoughtful, beautiful things that I loved, that meant something.”

He also introduced her to longtime friends like the comedian Lewis Black, who noticed, with his signature dark amusement, Mr. Linn-Baker’s near-instantaneous infatuation.

“It was like, ‘I can’t believe I met this woman,’ ” Mr. Black said. “He was bubbling over. By the third date, he was gone. And by the time we’d met her twice, we all said that if this didn’t work out, we were keeping her and dropping him. She’s terrific. She has a real joy.”

On Feb. 28, 2010, Mr. Linn-Baker told Ms. Justus that he loved her. (He keeps dates of significant anniversaries on his iPhone.) On April 3 he told Ms. Justus that she loved him. They had just returned from their first weekend away and after he asked if they might have dinner that night, Ms. Justus admitted that she had a date with someone else — and admitted to herself that her feelings for Mr. Linn-Baker were stronger than she had been willing to acknowledge.

She asked him where their relationship was headed, to which he replied: “I think you love me. And if you have to go out with somebody else to find that out, then go.”

Ms. Justus called the man and canceled.

On May 8 she made it official, inscribing the initials “TNIFILWMLB” on the receipt she had kept from their date: “The night I fell in love with Mark Linn-Baker.”

In February of 2012, Mr. Linn-Baker told Ms. Justus that they would be celebrating her birthday with a visit to the apartment of Marlo Thomas, his co-star in “Relatively Speaking” on Broadway, and her husband, Phil Donahue.

“I was trying to figure out how to pop the question, and where to do it,” Mr. Linn-Baker said. “I wanted some place that was really New York, because we both love New York. I wanted some place that was filled with love and filled with passion. And I’d gotten to know Marlo and Phil, and they’re crazy for each other, and they’re wonderful people, and they are New Yorkers, and they have a beautiful home. And I presumptively asked Marlo if I could propose in their living room.”

Ms. Justus and Mr. Linn-Baker walked in to find Champagne chilling and a cocktail spread, with Gershwin playing in the background. Soon Mr. Donahue excused himself. Not long after Ms. Thomas followed.

“Mark asked me to come over and sit by him on the couch, and he started saying beautiful things to me, none of which I can remember,” Ms. Justus said. She does remember saying yes.

On Dec. 29 the couple were married by the Rev. Jeddah Vailakis, an interfaith minister, at the Upper Crust, an event space in Greenwich Village. The bride wept as she walked toward the groom in a silver Ralph Lauren gown beneath a tree dripping with white flowers and tiny crystal lanterns and candleholders. Standing before a backdrop of birches and sculptures of wood and translucent paper meant to evoke chapel windows, Ms. Justus vowed to shine light in dark corners, and Mr. Linn-Baker promised not only to help each of them know what they wanted, but also to express it in words.

Afterward — amid 85 guests including the theater stalwarts Roger Rees, Amy Aquino, Jon Tenney, Leslie Urdang, Willie Reale and Jenny Gersten — Mr. Black toasted the newlyweds, imagining what their arguments are like: “ ‘I love you!’ ‘No, I love you more!’ They’re screaming back and forth at each other.”

“What your joy does for me is that it really, really irritates me,” Mr. Black said, “which makes me as happy as I can be.”