QMacGyver travels to a nuclear facility in Siberia where political prisoners are used for hard labor. Getting in as a motorcycle messenger, MacGyver makes contact with poet Yuri Demetri. MacGyver is there to get Yuri out and reunite him with his father, a defector. MacGyver picks up Yuri and drives over a loading ramp, jumping the fence and making good their escape.
Back in the U.S., MacGyver takes Yuri to his apartment while they wait for Pete to send a car. However, women's clothing is scattered around the apartment and MacGyver discovers that his friend Penny Parker has decided to move in. She's out of money after losing her last job and got in by telling the landlord she was pregnant with MacGyver's child. A smitten Yuri leaps to her defense. Penny explains that she's now working as a singing telegraph delivery person and needs to borrow MacGyver's jeep to make her first assignment. She quickly leaves before MacGyver can do much to object.
In a suburban home, hitmen Lyle and Vince are using a stereo system to torture Robert Julian, a Federal agent who they've captured. Also with them is Derek, the government employee who hired the hitmen. Julian learned Derek was involved and the hitmen are now torturing him to see who else he told.
Penny gets lost trying to find the address for the singing telegram. She stops at the hitmen's house and hears music from the stereo, and figures that's where the party is. Penny goes inside to the garage where they're busy and sees them kill Julian. She figures out something is going on and runs back to the jeep, backs it into the hitmen's car, and then drives away. They manage to write down the license plate and tell Derek to trace it, and then tell him to meet them later at a fish cannery that they're using as a base of operations.
MacGyver gets Yuri to the Phoenix Foundation where Pete tells them that Yuri's father has been relocated to New York. They'll relocate Yuri there the next day and he'll have to stay at the Foundation until then. Pete wants MacGyver to escort Yuri there and convinces him into giving up his apartment to do it. MacGyver arrives at his apartment by taxi as Penny pulls up in the damaged jeep. She tries to explain what happened and insists they have to rescue the man she saw being tortured. MacGyver gives in and they drive back to the neighborhood. Penny doesn't remember the address or what the house looked like and they eventually end up with nothing.
At the cannery, Lyle demonstrates the device he's made to carry out their hit. It's a voice-activated explosive pack that they'll attach to a wheelchair. Their target is Estevez, a Colombian government official arriving to testify against drug lords in his country. Derek arrives to give them a recording of Estevez' voice for the detonator. Lyle attaches one detonator to a wheelchair and demonstrates the device, blowing up the chair. He then gives a second detonator to Derek to plant on their target.
Back at MacGyver's apartment, Penny shows off the movie on TV that has her first two-second movie appearance as a silhouette. The station runs a news broadcast and Penny sees a news piece on Estevez's arrival. She spots Derek in the background and tells MacGyver. They check in with Pete the next morning, and he notifies the Federal authorities. Yuri and Penny chat, while Pete tells MacGyver that the government has hired the Foundation to handle security at Estevez's press conference. They've also found Julian's body, and learned he was in investigating a security leak in the Estevez case.
Derek meets with his superior, Jack Larson, who is wheelchair bound. Larson tells Derek that the Foundation will be handling security and that they know there's an inside man because of Penny's testimony. Larson tells Derek to make sure security at their end is tight. Derek checks in with the hitmen and warns them who Penny is. Once he tells the hitmen he planted the bomb, they dispose of him and go after Penny.
At MacGyver's apartment, Penny apologizes for causing so much trouble but MacGyver figures it's because she cares. Penny gets a call from someone ready to audition her for a commercial, but she has to be there in 30 minutes. Yuri arrives, having manages to slip out of the Foundation. MacGyver warns her that she can't go but she insists and Yuri insists on going to protect her. Pete calls to give MacGyver the news that Yuri has slipped out, and Penny and Yuri go out while MacGyver's tied up on the phone. Lyle and Vince grab them and drive away. MacGyver comes out in time to see Penny yelling for help. He tosses a road flare onto the van so that he can follow it far enough back that they won't spot him.
The hitmen go to the cannery, unaware that MacGyver is following them. They discuss their plans to go to City Hall to dispose of Estevez dressed as cleaning crewman, and then lock Penny and Yuri in a meat locker. Once they're gone, MacGyver comes in and spots the demolished wheelchair from the early demonstration. He scraps magnesium from the wheels, packs it into a pipe, then wedges the pipe into the padlock on the freezer door. When he ignites it, the pipe expands and breaks the lock. Yuri and Penny tell him what they overheard and MacGyver finds the workbench with the detonator components on it. He realizes what it is and they head for City Hall.
Pete greets Estevez as the official arrives at City Hall to make a press statement. The hitmen, disguised as cleaning crewmen, smuggle in weapons and then change clothes so they can pass as part of the security detail. Larson arrives in his wheelchair, unaware that Derek attached the explosive to the bottom. MacGyver arrives with Penny and Yuri and explains to Pete what's going on. They figure out that Derek planted the bomb on Larson's wheelchair, and Larson will be next to Estevez. Running into the conference room, MacGyver turns up the loudspeaker gain and stops Estevez from talking. When the hitmen draw their guns and prepare to finish off Estevez personally, MacGyver grabs a loudspeaker wire and pulls the unit down on them. Penny knocks the gun out of Lyle's hand and Yuri grabs it and holds him at gunpoint. Pete disarms the bomb and he and MacGyver thank Penny and Yuri for their help.