Diane is practicing language tapes at the laboratory to check her lab rats with the nanotechs. She notices one of them is catatonic and checks Jake's readings, which aren't good. She calls him but gets no answer, while at his apartment he's sleeping. Diane drives to his apartment with Kyle to discover that he's asleep and her screen was frozen.
The rat is still catatonic and Diane briefs Beckett that it was injected with nanites the same day as Jake. She also reveals that Jake is going to a wedding in Seattle for his friend, and he'll be acting as best man. Beckett isn't thrilled and wants to keep him there but Jake manages to convince her. However, he's going out there with Sarah, who is going with her friend Kevin. Jake is less than enthused.
In Seattle, Jake meets with his friend Alex, who tells Jake he needs to tell Sarah his feelings. Jake notices a guy walking around, but he's gone by the time he can ask Alex. Alex says it's probably his cousin Phil. Jake doesn't have much luck with the women and later at his room he sees Sarah and Kevin going into their room. When Jake enters his room, he gets to hear everything with his enhanced senses. Diane calls and he admits he doesn't think he's going anywhere. She doesn't mention that the rat is dead.
The next morning Jake wakes up to find Diane at his door. She says she's there to help him out by posing as a friend. However, when Jake has stomach pains Diane overreacts. He's called away for a paintball game led by Alex… with Jake getting chosen last. As they head out, Jake notices the man from earlier. Meanwhile Diane calls in to check with her assistant Fran, who doesn't have anything to report on the dead rat yet. The mother's bride pulls her away into a beauty makeover.
Jake uses his enhanced hearing to intercept his opponents, defeating two of them. Meanwhile Diane meets with Sarah and Diane is forced to explain why she's there when Jake didn't mention she was coming. Diane is also restricted in what she can tell about how she knows Jake.
In the field, Jake runs into Phil, who opens fire on him… with a real gun. Jake runs through the woods with Phil in hot pursuit, and Jake super-leaps over a fence to elude him. He catches up to Alex who reveals that Phil is a different man then the one who was chasing Jake.
Back near his room, Jake spots his attacker again and tries to cover for his jump. The man then goes into a room. Jakes marks the room number, then returns later and finds the walls covered with photos of him and files on the nanobot program. Jake figures the man is trying to capture him for the nano-tech. Jake makes a secure call to Beckett but can't get through. He checks with the desk clerk and tells him to send the police to 214, then Alex wants him to show up to give the speech.
At the wedding, Jake spots his stalker again and fumbles through his part. He also starts to feel a pain in his neck and Diane notices. She gets a call from Beckett who is checking back, and checks his readings on her PDA. As soon as the couple says "I do," Jake goes off in pursuit of the man but is temporarily immobilized by pain. He follows the man into the forest but collapses, and the man reveals that he's poisoned Jake. He heads back to the hotel while Diane gets a call from Fran with the autopsy report. The rat died of a massive concentration of nanites in his frontal lobe.
Diane goes to Jake's room where she finds the police looking for him, since they have him on security tape having broken into an empty room. Meanwhile, Jake has staggered into an empty section of the hotel with the man in pursuit. Diane finds him and explains that the nanites are killing him.
She gets him to her room and tries to convince him that he's hallucinating, while trying to override the nanites with her laptop. A now-paralyzed Jake tells her to reboot the nanites for a second, but Diane warns it will kill him. She finally agrees while Jake's hallucinatory stalker taunts him. Jake "dies" and Diane tries to revive him. Jake finally revives and briefly feigns amnesia to kid her.
Later at the reception, Diane checks in with Beckett and lets her know he's fine and she overreacted. Jake proposes the toast and gets through the heartfelt speech. Afterward Jake talks to Sarah who reveals that her friend Kevin is gay and she just brought him along so she wouldn't be there alone. When she asks to dance with him, he goes over to Diane and dances with her instead, saying she looks beautiful.