Will Travers stands atop the API building, peering at the cars and pedestrians below. Closing his eyes, he places both feet partway over the roof's ledge. He pauses a moment, then jumps back onto the roof.  appears to be watching from afar.

Tanya arrives at work, eyes bloodshot. In the women's restroom, Maggie hears her retch into the toilet.

In his office with Maggie, Will admits to feeling nervous about replacing David. "Don't be," she says. "Everyone's rooting for you."

Will visits the basement sanctum of Hal and asks for help researching the crossword patterns -- off the record. "That would be against the rules," Hal replies.

Will arrives late to Kale's office for an intake meeting. After the API teams receive their updated intelligence reports, Kale escorts Will upstairs to meet Spangler. "Don't let me down," says Kale. "I recommended you for this job."

Kale enters Spangler's office without Will. "How was D.C.?" he asks.

"Usual cockfight," Spangler replies. "Any more noise about the crossword thing?"

“Quiet as a mouse,” replies Kale before departing.

Spangler shows Will a photograph of the Russian missile broker Yuri Popovich with  and , although the latter two are currently unidentified, something Spangler wants remedied fast. "Twenty-four hours," he says. "Seem fair?"

"Very fair," Will responds.

At a law office, Katherine Rhumor attends the reading of her husband Tom's will. Her inheritance includes a townhouse that she was unaware her husband owned. Katherine also finds Tom edited his will the week before his death to leave her the  company.

Grant arrives late to a team meeting -- he was attending Career Day at his child's school -- and complains about the doughnuts Tanya brought. He prefers beignets. They need to concentrate on Popovich, says Will. "Why?" sulks Grant.

Katherine visits the townhouse and examines evidence -- a monogrammed bathrobe, books on the nightstands -- of his life there.

In the employee cafeteria, Maggie tells Will that Kale wants him to occupy David's office "to keep you closer." Will pays for Maggie's meal -- about as close as she's likely to get to a lunch date, she comments.

Eating with his team, Will learns that one of Popovich's companions has been identified as George Boeck. Will asks Grant about Career Day. "My kid thinks I'm unemployed," Grant grumbles.

"I tell my kids that I write secret video games," says Miles.

Hal informs Will that in 1983 multiple international newspapers published identical crossword clues. He hasn't determined who wrote them or why. "Keep looking," says Will. Hal objects that doing so could get him fired.

Katherine quizzes Tom's friend James Wheeler about the townhouse. "Tom wasn't cheating on you," he tells her. "Believe me."

"I really don't," she replies.

Will goes through David’s things packed in boxes and finds a picture of himself, his wife, his daughter, and David. Will then discovers a sheet of paper in David’s typewriter with letters typed in groups of three.

Will visits Ed Bancroft. "The morning of that train crash, David's car was parked in spot number thirteen," says Will.

"Impossible," Ed responds.

"Somebody else parked it, or he wanted us to know something was wrong," says Will. "What if he knew that train was going to crash?”

Will shows Ed the sheet of paper he found in David’s typewriter. "This is really old-school," says Ed. The letters correspond to a book's pages, lines, and letters. Ed admits that he wrote the crossword code. It was a go code.

"To start what?" asks Will.

Will applies the code to the road-food guidebook David gave him. "They hide in plain sight," the code spells out.

Walking by Miles's office, Will hears a television report about a Nigerian uprising. "No one listens,” says Miles, distraught as much that his advice on Nigeria was ignored as by his personal life. Will turns the TV off and recommends that Miles spend time with his family and return fresh the next day. After Will leaves, Miles turns the TV back on.

On the street, Will notices  following him. While walking home, he drops a rabbit’s foot that he had taken from David’s office as a memento, and, as he bends to pick it up, he narrowly escapes being hit by an out-of-control taxi. Working in his apartment, Will hears footsteps outside his door. He grabs a baseball bat, but the sound subsides.

A subdued Maggie meets Kale in a hotel room the next morning. "What you got for me this week?" he asks.

"Grant is jealous of Will," Maggie reports, something is freaking out Miles, and Tanya may have a "drinking issue."

Kale asks if Will seems "distracted by David's death, anything like that." Maggie says no. At the office, Hal informs Will that the 1983 crossword clues were published after the bombing of a marine barracks in Beirut. The day after the clues appeared, supporters of the Lebanese terrorist group Hezbollah, the attack's sponsor, disappeared. “Go code initiates revenge killings," says Will.

At her home, Katherine finds a four-leaf clover left for Tom by . "Lucky, lucky, lucky," she says.

James Wheeler expresses concern to a man he calls R.C. that Spangler is becoming overzealous. "He knows what he's doing," says R.C.

"He's getting older," says Wheeler. “We all are.”

Spangler interrupts a conversation between Will and Maggie. "You'll have something on my desk this morning regarding Yuri?" he says.

"Absolutely," Will replies.

Will meets with his team. Miles lies about relaxing with his family. Grant extols British colonial institutions, specifically their "standards of behavior."

"Doughnuts every morning?" chimes in Miles.

"Exactly," says Grant, just as Tanya appears with beignets.

When Grant responds flippantly to Will’s questions about Yuri, Will responds furiously calling Grant a "lazy, pompous piece of shit" and demands information by the end of the day. The team slinks silently away.

Will again stands atop the building. "Maybe he'll jump this time," says .

"No such luck," says .

"He's looking right at me," says .

"Relax," replies . "He's going back down."

A woman and three children play hide-and-seek in the snow outside a patrician brick mansion. Inside, her husband opens the morning paper and discovers a fresh four-leaf clover, which according to  means . Moments later, he points a gun at his head. Outside, his wife hears a single gunshot.

The same day in Lower Manhattan, Will Travers arrives at the American Policy Institute, a federal intelligence agency. Tanya MacGaffin, a fellow API analyst, asks for help solving a crossword entry. Will supplies the answer: Marsilea quadrifolia, the Latin word for four-leaf clover.

From his office window, Will observes a man (David Hadas) exit a car and sidestep the "13" painted on the adjoining parking space. Will's coworker Maggie Young enters his office and quizzes him about the date. It's his birthday, Will realizes. Maggie invites him to lunch.

Will and three other analysts -- Tanya, Miles Fiedler, and Grant Test -- enter a conference room. Grant chides Tanya for failing at what he considers her "most important job," remembering the doughnuts. David Hadas, the team’s boss, and the superstitious man Will observed, bustles in bearing the team’s assignments. Will's involves a Russian missile broker named Yuri,  and .

At lunchtime, Will declares himself too busy to join Maggie, then sets his work aside to peruse several daily paper's crossword puzzles. Later, he informs David he has found identical references to the three branches of government across several papers. The clover entry, Will theorizes, is related. "What or who does that fourth leaf represent?" he asks.

David dismisses the references as a joke among crossword editors, but notifies his boss, Kale Ingram. "Anybody else see this?" Kale asks. "No," replies David.

In the cafeteria, Miles and Grant give Tanya, a recent hire, the lowdown on her colleagues. Truxton Spangler, the agency's unapproachable director, for instance, eats cornflakes for lunch every day. "Why is Will Travers so mopey?" Tanya asks. Miles replies that his wife and child died on 9/11 and Will had been scheduled at the World Trade Center that morning, but arrived late. "He's never been late for anything since," Grant says.

Will grabs lunch at a street cart where David joins him. Will expresses doubts about his job and hints at resigning. David gives him a birthday present, a guide to road food. "I don't blame you for taking stock," says David.

The problem isn't his work, Will says, but rather being unable to discuss it. "That's the hardest thing in this job," David replies. David invites Will to dinner. Will declines. "Days like these," he says, remind him of his family. "I miss them too much."

As he departs, David hands Will an envelope and says, "Don't open it until you get home." Outside his apartment, Will opens the envelope to find a key attached to this note: "Drive away. Don't look back. It's time."

Will notices a Norton motorcycle parked curbside and calls David. "I can't keep this," he says. "I can hear you smiling," David replies. "Why now?" asks Will. David says that he'll explain everything in the morning. He's taking an early train out of Putnam station; Will is to meet him at a bar.

The next morning, a man dressed similar to David (but whose face is never seen) walks down a train's aisle. Seconds later, a train speeding in the opposite direction switches onto the first train's track.

Will drinks coffee at a bar. On the TV news, coverage of the death of the mansion owner, revealed to be Thomas K. Rhumor, is followed by word of a train collision near Putnam station.

Kale delivers the eulogy at David's funeral. David, it turns out, is Will's father-in-law. After the funeral, Kale offers David's position to Will, who expresses hesitation. "Think it over," Kale replies. “If your mind doesn't change, I'll accept your answer -- and your resignation."

That evening, Will sits in David's office. The phone rings. "Knight to king's bishop three," says the caller, who hangs up after realizing that David hasn't answered. Will locates a chessboard (inside a globe) with a game in progress. An inscription on the board reads, "From one pawn to another -- E.B."

Still that night, Will rings a doorbell. "Are you Ed Bancroft?" he asks the weary man who appears. "David's been killed," Will informs him.

Will tells him around the office that people say, "You were a genius at cracking codes, until the codes cracked you." Will presents the crosswords but Ed claims not to recognize them. "They showed up the day before David died," Will replies. "Coincidence?" Ed abruptly asks Will to leave.

As Will heads home, a man named  shadows him on the Putnam station platform. Will notices David's car in the lot. The man shadowing Will drives away. David's car is parked in space 13.

Will visits Maggie in her home, apologizing for the hour. The superstitious David would never have parked in space 13, Will maintains. "His remains were identified," counters Maggie. Will needs to accept David's death and move on.

At work the next day, Will informs Maggie that he's resigning. This ensures Grant's promotion, she replies. Miles corners Will later and insists that David would want him to "pick up the torch."

When Will unexpectedly accepts the position because , Kale reacts curiously and asks "What changed your mind?” "You know what? I don't care," he continues. "Let's introduce you upstairs." Upstairs, an aide tells Will that he’ll meet Spangler tomorrow.

Spangler disembarks a ferry and is driven to a country home in . He enters a meeting in progress. "Anybody double check that Tom is actually dead?" he asks. "He blew his brains out," replies . "I saw his body."

"Good," says Spangler. "We're back on track."