At the Smoke Creek Farm, stable owner Kyle Larson tells boss George Henderson that he's through and refuses to fix another race. He throws a jockey's crop on the floor and Henderson's henchman Mick Underwood tells him to be careful. Henderson throws Kyle in a stable then activates an electronic device in the jockey's crop. All of the horses go berserk, including the one in the stable with Kyle. Underwood tries to turn off the crop but the horse stomps Kyle to death. Kyle's daughter Jenny comes to investigate and Henderson and his man make a quick exit while Jenny finds her father dead.
MacGyver and Jack return to Jack's hanger and MacGyver is less with Jack hauling him off on a pottery-finding mission. Jack isn't happy MacGyver dumped the pottery to keep them from crashing. Jack checks his messages and finds a call from Jenny Larson, who has been trying to reach them for days. She tells them that Kyle is dead and the police think it's an accident, but she's found something and doesn't believe the official account. The guys head off to the farm and comfort Jenny. She notes that all the horses were going crazy that night, and shows MacGyver and Jack an electronic component she found in the stables. Jenny knows about Henderson and explains that her father went to him for money, and bought the mortgage from the bank to get control of Kyle. She finally admits that her father started drinking and became irritable, then told her he'd fixed a couple of races. Kyle said he was going to confront Henderson the night he died. She thinks that it involves her horse Jenny's Chance, and Henderson tried to buy the horse from her at her father's funeral. MacGyver notes that the stable belonging to Jenny's Chance isn't damaged like the others, and Jenny explains that the horse is deaf. MacGyver tests the component and determines it's a microspeaker that emits an ultra-sonic signal that affects all the horses except Jenny's Chance. He warns that it will be difficult to prove Henderson is involved.
Henderson meets with Underwood, who is working to make a new microspeaker. He warns Underwood that he needs it working in time for the race the next day.
At the Phoenix Foundation, Pete does a check on Henderson and determines he's laundering $1.5 million for a Cuban drug lord called "Lucky Charlie." They meet with FBI agent Colin Yardrow, who has been trying to tie Henderson to the race-fixing scam. Lucky Charlie managed to get away with the FBI money they used in their sting operation in Florida. Lucky Charlie and Henderson have never met and do all their business by phone. Colin has tapes of their conversations and MacGyver comes up with a plan.
Later, Pete and Colin go to see Henderson and Pete identifies himself as Harry Boyle. He wants to buy Jenny's Chance and claims he's in "acquisitions." Pete offers $200,000 in cash for the horse but Henderson refuses to sell. An angry Pete gives him 24 hours to reconsider and tells Henderson he can be reached at the Derby Grill. MacGyver, Jack, and Jenny watch from a distance as Henderson tells Underwood to follow Pete to the restaurant. MacGyver figures they took the bait and the trio follows Underwood to the restaurant. Pete and Colin arrive: the entire restaurant, the staff, and customers, are part of the FBI sting.
Underwood arrives at the restaurant and takes a seat near Pete. MacGyver and Jenny come in and stage a conversation with Pete. MacGyver pretends to be a nerd genius named Dexter Fillmore who they've hired to make a microspeaker. Pete threatens MacGyver, telling him he needs the device by the race on Saturday. Underwood overhears the entire conversation and Jenny insists that they need Jenny's Chance for their plan to work. They go downstairs to watch the race and Underwood calls Henderson to tell him the entire thing is a front. MacGyver and the others listen in as Henderson hears that Jenny's involved. He goes to the restaurant while MacGyver calls Jack and tells him to go in. Jack drives up to Henderson at the farm and tells him he's Lucky Charlie. Jack claims he's on the run and needs the rest of his laundered money tomorrow. Henderson warns he needs another six weeks to launder the remaining money, but Jack insists on getting the money the next day. He notes that if Henderson can't do it, he knows someone else who does. Henderson reluctantly agrees to complete their deal.
Henderson meets with Underwood and tells him what happened. MacGyver leaves the restaurant and Henderson grabs him at gunpoint. He takes MacGyver back to the stables and Underwood studies his ultrasonic transmitter plans. Henderson wants to know what MacGyver is doing for Jenny and shows him the jockey's crop with Underwood's ultrasonic transmitter. MacGyver "spills" that he knows what they're talking about and they threaten him by driving one of the horses berserk. He finally gives in and tells them the full story, admitting he couldn't create the device. MacGyver claims he's a computer expert and set up Pete's gambling set-up. He's patched in his system to a thousand bookie joints and Pete handles millions. Henderson and Underwood take MacGyver and go the restaurant.
Pete and his team swing into action and they run a tape of a previously recorded race. Jenny watches the entire thing through a two-way mirror. MacGyver takes Henderson and Underwood downstairs to Pete's bookie joint. Jack is there as Lucky Charlie and Pete is showing off his business. Henderson announces himself and Jack tells him that he's using Pete to launder his money. Pete insists he can launder Jack's money overnight and tells MacGyver to show Henderson the system. MacGyver claims he can make their bets a nanosecond before the tracks close the betting to avoid changing the odds, and Pete boasts they send the money to Chicago and then distribute the money in payoffs all across the country. They can give Jack a six-to-one payoff. Henderson points out they need Jenny's Chance to guarantee a win. Pete says they'll have Jenny ride, and proposes a partnership. Henderson agrees to a 50/50 partnership and Jack warns them all against a double-cross.
That night, the team goes over their plans and Pete warns they need Henderson to pay off in the marked money and then get a confession. However, Colin comes in to tell them that the real Lucky Charlie was seen but was injured and got away from the police. The information has gone out on the news before the FBI could stop it. It's risky but everyone insists on going ahead with the plan.
The next day, Jack goes to the farm and fakes an injury. Henderson has Lucky Charlie's money but reveals that the real Lucky Charlie is there, similarly injured. He demands answers and Jack claims he's running a scam on Pete. Jack warns they can't kill him or it will mess up the deal, so they tie Jack up and take him with them.
At the restaurant, Pete checks with MacGyver in the computer room and they prepare to get Henderson's confession. Henderson and Lucky take Jack in along with the $1.5 million. They tell Pete that Jack is a conman and Pete has him confined, then says he doesn't buy the fact they’re making a switch and tells them to get out. Lucky Charlie insists that they Pete goes ahead and takes his $1.5 million. Pete reluctantly agrees, and MacGyver and Colin confirm that it's the marked money from the FBI sting. Meanwhile, Lucky Charlie grows suspicious and Henderson tells him to calm down. Pete claims the race is on a live satellite feed but Lucky Charlie says he saw the race last week. He shoves Pete into a table, revealing a video player. Lucky Charlie accuses Henderson of setting him up and throws the player through the mirror, revealing Jenny on the other side. Jack goes for Henderson, who shoots and kills him. Jenny accuses Henderson of killing her father as well and Henderson admits he had to do it to stop Kyle from going to the police. With that, Pete says they've got what they want. The man dressed as "Dexter" reveals he's Steve and has a tape of the whole confession. FBI agents arrest Henderson and Jack gets to his feet, unharmed. "Lucky Charlie" removes his mask to reveal... MacGyver. Jack explains that MacGyver switched Henderson's gun for one with blanks, and Pete tells Henderson that they arrested Lucky Charlie an hour after the story broke. They play back a video recording of Henderson's confession for him then haul him away as the team celebrates.