Convicted killer, Prisoner 9-1137, is released after servicing sentence, with only $2,000. A man meets the killer in the parking lot and reports that the target is camping. He provides a map to the killer but warns that the target has two friends with him. The man gets no response when he asks why the killer wants to talk to the target first, and collects his $2,000. The killer leaves in a car.
Jack Dalton has convinced MacGyver and Pete to accompany him to the mine that he won the rights to in a poker game. Pete and MacGyver are doing the work, with MacGyver building a makeshift filter. Jack provides the motive power but ends up soaking Pete. All they get for their efforts is enough gold dust to cover a fingertip.
The killer arrives on the road near their site and locates MacGyver's Jeep. After donning a camo mask, the killer heads into the woods.
Pete warns Jack that he's always taking shortcuts, like the time he bought a third-hand plane and MacGyver had to make a mid-air repair. Jack suggests that they look upstream and try to find the mother lode. MacGyver reminds him of the problems they had the last time they went into a mine, and how Jack manages to inevitably drag them into trouble. Pete decides to go fishing while MacGyver and Jack go scouting. The killer arrives and knocks him out, then fires off several shots.
Upstream, MacGyver and Jack hear the shots and go to investigate. They find Pete's abandoned tackle box, his hat, and his rod. MacGyver takes the telescoping rod and finds two sets of tracks. Realizing Pete's been abducted, they go into the woods after him.
Pete tries to get answers from his abductor without success, and the killer takes him to a nearby cliff. Meanwhile, MacGyver and Jack find Pete's Phoenix Foundation ID and figure he's trying to leave them a trail. They wonder who could be responsible and suspect Matt Weber, who tried to oust Pete as Phoenix Foundation director and take his place. They can't figure why Weber would drag things out, and suspect Murdoc, who has a grudge against all three of them and is known for playing games.
The killer ties Pete up near the cliff edge and then backtracks. MacGyver and Jack find Pete's wall and check it carefully for booby traps. When it doesn't reveal anything useful, MacGyver sends Jack to the nearby grocery store to call the police. The killer watches MacGyver and removes her camo mask, revealing she's Deborah. She remembers how she was hired to kill MacGyver when he led an environmental investigation against a company. Shaking off her memories, she goes after Jack and captures him at the jeep, then forces him to drive to her car.
MacGyver finds Pete's wristwatch along the trail, unaware that Deborah has taken Jack to Pete's location and tied him up as well. She explains that she has unfinished business with MacGyver after he escaped her attempts to kill her. Deborah plans to use them as bait to lure MacGyver to her.
MacGyver follows the trail to the jeep and finds Jack's pilot's cap and a signed note from Deborah saying they're at the cliff. MacGyver remembers how Deborah's attempt to kill him left him blind, and he managed to knock her out by luring her into a puddle and using jumper cables.
Going to the cliff, MacGyver moves through the woods to try and rescue his friends. Deborah is aware he's nearby and tells him to come out or she'll kill Jack and Pete. MacGyver reveals himself and Deborah explains that she failed for the first time in the career when he defeated her. She believes that she let her feelings for MacGyver interfere and decided to test them face-to-face. She looks him in the eye and then starts to pull the trigger. Jack manages to kick a rock at her , distracting her long enough for MacGyver to disarm him with Pete's fishing rod. She tries to recover her gun and Pete trips her, causing her to fall off the edge of the cliff. She grabs a root but then discovers a ledge below. Deborah pretends to be hanging on and begs MacGyver to rescue her. When he tries to pull her up, she draws a knife and tries to stab him. She scratches his arm but the ledge gives way beneath her and she plummets to her death.
Later, the police take Deborah's body away while Jack wonders why she tried to kill MacGyver when he was trying to save her. Pete compares her to the scorpion in the story of the scorpion and the turtle, which killed itself despite the fact it ended its own life in the process.