Officer Nik Radinski is on crowd control as the police secure a building for a visit by Litvanian freedom fighter Alexsander Kudesko. At Intersect, Leonard and Sam review the video and Leonard notes that Alexsander has avoided several assassination attempts in Europe. However three weeks ago Nik took a vacation in the mountains, but popped up in the Litvanian capital. They suspect he's in a plot to kill Alexsander, and wants Sam to keep him under surveillance. Intersect is having Sam infiltrate the police department.
Later, Sam reports for his first day at his new job. Nik comes over and introduces himself to his new partner, and warns him that he'll be in for some surprises on his ride with him. The two men hit the streets and Nik talks about how his parents came from Litvania and a lot of people live in the neighborhood. He says that he's never been in Litvania in his life. A woman, Mrs. Stapola, waves them over and tells Nik that she has to talk to him alone. They go into her flower shop and Sam turns invisible and follows them in.
Mrs. Stapola says that they're back again and she's afraid, and gives Nik their location, Ernie's store. He says that he'll handle it and leaves, and Sam gets out to the street ahead of him. They drive to the location and find a car parked outside. Nik says that it belongs to Frank and Rudy Ross, and they run a protection racket in the neighborhood. They hear a crash inside and run into the grocery store. The thugs claim that Ernie just slipped and fell, and the intimidated owner agrees. Nik tells Ernie to stand up to them, but Ernie points out that they'll be out on bail and the police can't protect him forever. When Nik grabs Frank, he just smiles and says that Nik doesn't want to violate his civil rights. Nik has no choice but to leave with Sam.
Outside, Nik figures that if they could get one shop owner to stand up to the Ross brothers then the rest would do so. He then claims that the Ross' car is in a tow away zone. He uses the squad car to push it into the zone and Sam warns him that it's illegal. Nik says that it makes him feel good and calls for a tow truck. Meanwhile, Sam goes in the back alley, turns invisible, and enters the store. Ernie says that he can't pay, and the Ross brothers start smashing up the place. Sam shoves Frank and Frank assumes that Ernie did it. The invisible agent knocks Rudy as well when he goes at Ernie, and they run off only to see their car being towed off. Sam comes out and turns visible, and Nik has no choice but to figure he convinced Ernie to stand up to the thugs.
Nik and Sam go to lunch at an outdoor cafe, while two men watch them and take pictures. They figure that Sam is up to something since he just joined Nik two days before Alexsander's visit.
Later at the station, Nik is telling his fellow officers about an incident from the old days. He then takes Sam with him to a Litvanian nursing home and says that a friend got out of the hospital and he wants to see how she's doing. Sam invisibly follows him to a room where a woman is staying. Once Sam turns visible, he finds a phone booth and makes a call.
Nik tells the woman, Lisa Korlavitch, that he can leave very soon.
Sam tells Leonard that Nik is visiting his girlfriend and it has nothing to do with the case. Leonard tells him to stick with Nik and wonders if Sam is getting emotionally involved. Sam admits that he is but figures that Nik is a hell of a cop.
Nik gives Lisa an engagement ring and puts it on her finger.
Leonard tells Sam to find out Lisa's name. Sam turns invisible and heads for the admission desk.
Lisa dozes out and the nurse assures Nik that it's only the sedation. Another patient, Josef, comes in and assures Nik that it's under control. Nik hesitantly agrees and leaves.
Sam goes through the records and then leaves. He turns visible just as Nik comes out, and Nik complains that Sam didn't stay with the car. Sam asks if there's anything wrong besides Lisa, and Nik insists that there isn't.
At Intersect, Abby and Leonard meet with Aleksander. Leonard has recommended that Aleksander not attend the rally, reminding him of the other assassination attempts. Aleksander refuses to surrender to the enemies of freedom, and insists that his safety isn't important. Once he leaves, Leonard goes over the plans.
Josef and the nurse, Kristina, rig a bouquet of flowers to emit a fine mist of poison to kill Alexsander. She assures Josef that she'll be close to Alexsander thanks to Nik. The two men bring photos of Sam and Nik, and Kristina recognizes Sam as an Intersect agent.
As they patrol the streets, Nik receives a message that he got a call from nursing home. They pull over at a phone booth and Nik calls Lisa. Kristina answers and says that Lisa is fine, but his new partner is an Intersect agent. He figures that they know about the plan and should call it off, but Kristina says that they don't know and won't find out. She says that Sam will die in an "accident." When Nik refuses to help, Kristina says that they've moved Lisa to a more secure place. He has no choice to agree, and Kristina describes how a burglar alarm will go off at an import company. She tells Nik to have Sam go into the delivery entrance and they'll take care of the rest. When Sam asks for details, Nik angrily tells him to get off his case.
At Intersect, Abby confirms that Lisa is a Litvanian national with the U.S. trade mission. She was recalled months earlier.
That night, Nik parks on a street corner with Sam and checks the time. Meanwhile, one of Josef's men, Carl, sets off the burglar alarm and Sam says that they should check it out. After a moment, Nik drives to the import company. He has Sam take the delivery entrance, but then stops his partner and says that it's a set-up and he's going to take care of it. Sam agrees to go in with him and Nik tells him to wait while he flushes him out.
Once Nik goes inside, Sam turns invisible and flushes out Carl. He knocks Carl out and turns invisible, just as Nik runs back.
At Intersect, Leonard interrogates the shooter but he says nothing. Leonard then demands answers from Nik. Nik says that he met Lisa at the trade mission and they fell in love. Lisa disappeared for two days and Nik found out that they sent her back to Litvania rather than let her marry an American. He went to Litvania to get Lisa and they were secretly married there. Nik couldn't get her out of the country, and Josef and Kristina approached him and claimed that they were in the underground. Eventually they got Lisa to the States, and threatened to kill her if he didn't help them kill Alexsander. Once they gave him h is final instructions at the rally, they would free. Nik asks Leonard not to cancel the rally for fear that they'll kill Lisa. Sam suggests that they put out a fake news bulletin that Sam was killed, and then they'll get Lisa back when they come after Nik at the rally. Leonard reluctantly agrees despite the risk, and Sam assures Nik that it will work.
The next day at the rally, the police patrol the area as the Litvanian residents gather. Abby and Leonard are waiting outside the building, and Leonard checks in with Sam and Nik on the outskirts of the crowd. Alexsander finally comes out and addresses the crowd.
Kristina prepares the sprayer with the poison and puts it in the bouquet. She then works her way through the crowd, and Nik spots her. Sam slips away, turns invisible, and then goes after Kristina. Kristina joins Nik and points out that Lisa is across the street in a van. She'll be released after Nik lets her through. As Alexsander finishes his speech, Nik lets Kristina through. She goes up onto the stage but Sam knocks the bouquet out of her hand. When she goes for a gun, Sam knocks that aside as well and runs through the crowd.
Turning visible, Sam takes a police motorcycle and goes after Josef as he drives off in the van. Nik sees him, gets into the squad car, and drives after him. The van reaches the highway and Sam manages to catch up to it. He grabs a ladder on the back and jumps on, and then climbs up to the roof. Sam then turns invisible, gets in on the passenger side, and grabs the wheel. The van goes off the road and Sam knocks out the man guarding Lisa. Nik pulls up as Sam turns visible and is reunited with his wife.
Later, Mrs. Stapola gives Lisa some flowers as Sam and Nik look on. Sam tells Nik that there'll be a Congressional investigation of the espionage ring, and Lisa won't be allowed to leave the country since she's a witness. Nik thanks his friend for his help, and says that he can always come back and ride patrol with him.