On a quiet night at a local college campus, two campus security guards investigate a reported break-in at the aquatic center. They rush to the scene to find a naked suspect running up the flight of stairs to the top of the high dive. Guns pulled, the officers order the suspect to step into the light. Could it be a fraternity prank or a deranged homeless person? No, it's Detective Michael Britten. Assuring the guards everything's okay, Britten tosses his badge from atop the high dive. The guards holster their weapons and ask what's going on. "It's kind of hard to explain," Britten says.
A failed car bomb attempt brings Marcus Ananyev into Britten and Bird's interrogation room. Marcus is an accountant for the Russian crime lord Maxim Basayev. The detectives offer Marcus the only way out: enter the witness relocation program and testify against Basayev. Marcus is hesitant, fearing his wife's reaction. She knows nothing about his work for Basayev. When Britten suggests she'd rather have a live husband than another flat screen TV, Marcus explains, "You don't know my wife."
Later, Alina Ananyev arrives at the police station feeling betrayed since Marcus has been lying to her for two years. She rejects his assertion that everything he did was to provide her with the life she wanted. Once Britten mentions they can only pack one large suitcase each, Alina tries to leave, but Britten talks her into staying, assuring her that Baseyev will find her. When Britten and Bird drop the couple at a motel room, which they cannot leave, Alina physically attacks Marcus, furious for being put in this situation. Britten pulls her off and tries to calm her down. Alina questions Britten's claims that everything is going to be okay. "Everything we have, I have to leave it all behind," she says. "How could you possibly tell me it's going to be okay? You can't even begin to imagine what that feels like."
Britten connects Alina's anguish about leaving everything behind to Hannah, who's packing their possessions to donate to Goodwill in preparation for the move to Oregon. Tired of waiting for Britten to help with the project, Hannah's almost finished. Britten pokes around the boxes and feels nostalgic for each item Hannah wants to give away. When Britten asks to delay the Goodwill vans until he's had a chance to make sure she's not giving away things he'd like to keep, Hannah believes this is merely another excuse to delay their moving process.
Britten takes Vega to an old steakhouse to introduce his informant, Jake. With Britten leaving soon, he's hoping Vega and Jake can work out a similar relationship, though Jake seems resistant. When he suggests a celebratory steak dinner, Britten declines, handing over some cash to pay for dinner instead. Later, the partners follow one of Jake's leads, performing a stakeout at the nearby Palace Electronics building. The burglars never arrive. Vega speculates Jake gave them a bad tip because of the way Britten coolly handed off Jake to Vega without any acknowledgement of their 15 years working together. Since Jake has never led Britten astray before, maybe Vega is right.
Britten wakes up to a frantic phone call from Bird. Alina's left the safe house and no one knows where she is. Marcus wishes he died in the explosion. At least then Alina wouldn't be in danger. Marcus has no idea where she could've gone or with whom. He was always working. Britten finally asks, "Do you even know your wife at all?" "I guess about as well as she knew me," Marcus says. Despite having grown apart, Marcus loves his wife and wants no part of the witness protection program without her. If they can't find her, he won't testify. He'll do whatever he has to do to keep Alina safe, even if it means giving himself up to Baseyev.
Bird and Britten try to track Alina down. Looking over past credit card records, Britten notices a place called the Palace Hotel in Palm Springs. The name reminds Britten of the Palace Electronics building from Jake's bogus tip, so Britten decides to start there, much to Bird's dismay. Asking around at the Palace, Bird and Britten discover Alina wasn't alone when she stayed there. The bartender is able to retrieve a name from the credit card receipts: Greg Hollander. The detectives head off to his house.
The Russian mob know about Greg as well and have already taken him hostage in his home. As Bird and Britten approach the house, Greg knocks over a table to get their attention. The Russians try to flee the house, and a gun battle erupts; but the detectives are able to rescue Greg. Afterwards, Greg insists he's Alina's friend, not her lover. He's a male escort for men. Alina only wanted Greg for companionship since Marcus was always working. Alina always talked about how happy she and Marcus used to be and how sad they'd become since they'd grown apart. Britten has an idea and calls Marcus. "That young couple that you were; if you ran away together, where would you be?"
Based on Marcus' information, Britten proceeds to an old beach motel and finds Alina staring out at the ocean. She can't decide between entering witness protection with Marcus or by herself. While she never knew what Marcus did for a living, she knew it changed him... and it changed her. Britten tries to rekindle their relationship by saying one suitcase may not seem like much into a new life, but if she's with the man she loves, Alina might not need to take anything. Alina decides to give her marriage another chance and returns with Britten to the safe house.
Britten wakes up early the next morning to help the Goodwill employees pack up their donation trucks. Hannah is surprised to see Britten so involved. Later, she asks when he had a chance to go through the boxes. Britten admits he never had a chance. He merely figured whatever Hannah thought to toss was fine by him. Perhaps Britten's words to Alina hit home. When Hannah asks what changed his mind, Britten simply smiles, "I slept on it." Furthermore, he's got a surprise in store for Hannah after work.
Britten visits Jake, who confesses to being upset by the way Britten tried to hand him off to Vega. After all, he considers Britten a friend, even if he's a cop. Britten apologizes, telling Jake he's going to miss their dinners and talks. As a plus, Britten admits it was Vega who said he was being a jerk. Jake decides to have dinner with Vega after all to see how they click. Oh, and the tip he gave them earlier was correct, just with a few wrong details. He'll give Vega the right ones.
That night after their dinner date, Britten brings Hannah to their old college swimming pool. Britten wanted to bring her back to where it all started, the place they first met. The couple takes a stroll down memory lane, recalling their early days. They talked and talked until the pool closed. Britten remembers one more element: they jumped off the high dive together. Want to do it again? Hannah's hesitant, yet she loves this new spark in Britten. Soon enough, their clothes are off and they're jumping hand-in-hand into the pool. Hannah and Britten's giggling doesn't end even after they notice a pool sensor sending out an alarm. Instead, Michael hides Hannah in the corner and starts running up the high dive stairs to fetch their clothes with a huge smile on his face.