In northern California, a police officer chases Mac and Jack down the highway in their rented lime-green minivan. Mac drains the contents of a road flare into a plastic cup and tells Jack to pop the hood. Once Jack does so, Mac has him wedge the folded plastic cup under the hood edge after connecting a wire to it. Once he does, Mac blows the hood off and then climbs out the skylight and to the engine. He pours a chemical into the engine, feeding it oxygen and speeding them up so that they can outrun the police car.
Eight Hours Earlier
Jack is driving Mac, Riley, and Wilt to Mission City, and Mac has brought along gallon jugs of chemicals. Wilt tells Jack to relax but Jack isn't convinced. Mac says that he hasn't been back to their hometown in five years, and Wilt points out that their old teacher Arthur Ericson has invited Mac to come talk every year. Wilt talks about the girl, Darlene Martin, who Mac invited to prom and got shut down. Riley says that she spent most of her high school teaching herself to hack computers. Wilt says that it's nice seeing her face without a screen in front of it.
They arrive at the junior high school and Riley reminds Wilt not to say anything about Phoenix. Arthur comes out to welcome Mac, who introduces his friend. The teacher warns that some of the faculty haven't forgotten him for "the incident." The class bell rings and Arthur introduces Mac to his science students, talking about how he used to disarm bombs. They're less than thrilled to hear that he works with a think tank. One girl finally asks Mac if he built a four-cylinder engine in sixth-grade, and he confirms that he did. He starts talking about the preferred manner to fix an engine, and realizes that everyone is bored except the girl who asked the question.
Wilt shows Jack and riley his locker and talks about how Mac was bullied. He broke the bully's nose and get suspended, and then Mac helped him with his homework every day. Wilt says that he swore to never talk about "the incident." As they go, Jack and Riley agree that they're not leaving town until they learn the details.
Mac creates a chemical recreation and everyone applauds. Afterward, Arthur tells Mac that he has a knack for teaching, and he's keeping the lab open after school. The girl, Valerie Lawson, stays and Arthur says that she's a multi-field scientific genius. However, her grades started dropping a couple of months ago, just like how Mac's grades dropped when what happened with his dad. Valerie is from a single-parent home and hasn't said anything in weeks.
Mac goes over to talk to Valerie about the robot arm she's working on. Two thugs come in and punch Arthur when he asks them to leave. Their leader, Karl, tells Mac to hand Valerie over. He pours liquid nitrogen into water, causing an explosion. However, a third man attacks Mac and delays him long enough for the second thug to grab Valerie. Karl tasers Mac and tells him that if anyone calls the cops then Valerie is dead.
Later, Wilt and Riley take Arthur to the ER and Riley gets into the school security system to get footage of the kidnappers. Mac and Jack drive out to the Lawson home and knock on the door. Valerie's father Frank finally opens the door and explains that someone called him at work and told him to come home and wait. He worked in rally cars until he lost his wife Kelly, and then retired to raise Valerie. Frank suggests that they leave and let him handle it, and Jack and Mac agree. Outside, Jack figures that Frank is in it but Mac doesn't believe it and picks up one of the solar-powered sidewalk lights.
The two men park down the street and Mac starts to break open the dashboard. When Jack objects, the choice is between Jack's bank account or a missing kid. Once Jack agrees, Mac removes the CD player and says that he's going to use the laser from that combined with the photocell to create a crude laser-based microphone to hear what's going on inside. One he does so, they listen as Frank calls and tells someone that he promised not to call anyone for help and the kidnappers are going to call to negotiate.
Wilt and Riley go back to the school and Wilt tries a side door. It's locked, and he insists that they only broke in so Mac could do after-hour science experiments. Wily explains that there's a skylight they used to climb up to via a tree, and discover that they cut the tree down. While he tries to work a way up to the skylight, Riley picks the lock on the door with a hairpin and they go in.
Riley hacks into the security system and they find the footage of the three thugs taking Valerie away. They get a partial plate on one of their cars, ad Wilt takes a photo of the partial.
As they wait for the call, Jack talks about why Mac never came home. Mac says that coming home for him is complicated, and Jack says that it's okay for him to come home occasionally and remember what makes someone themselves. as Mac reluctantly agrees, and Riley and Wilt call to say that Wilt called Justin Wright, one of Mac's high school bullies, to identify the customization job. There's only one person in Mission City who does that kind of customization: Frank. Mac and Jack head back to the Lawson home, just as Frank away.
Jack calls Riley to have her confirm that Frank didn't get any calls on his landline. Mac checks the tire tracks and realizes that Frank drives a hybrid and has special suspension. He also finds red clay that came off of the tire, and realizes that there's an old logging road with the mud. As they drive out to the logging road, Jack continues pushing Mac. Mac says that he feels guilty because it's where he lost his mother. Jack talks about how he was miserable after he lost his father Jack Sr., and one day he finally took out the GTO that they rebuilt together. He says that Mac's mother would want him to be happy,
Patricia calls and Jack and mac discuss what to tell her about the off-the-books mission that they're on. They ignore it and Riley calls to say that Patricia has been calling her. She calls Wilt and asks about the team, and says that they have another op coming up in 48 hours and needs everyone back. Wil says that they're at the movies so he had everyone turn the phones out. He claims that he's out walking and wrapping his head around everything he's learned, and quickly hangs up claiming his reception is bad. Riley says that Wilt told a horrible cover story, but Mac figures that they need to focus on finding Valerie.
The two agents find a cabin on the logging road and spot Frank. Mac plugs the exhaust on his car so Frank can't drive off. Frank says that they've killed Valerie, and Jack finds a duffle bag full of money in the back seat. The father finally says that the guys came to him and had him do some driving for them. Jack realizes that the money is drug money that Frank is going to smuggle for them, and Frank had to take the job to keep his family going. A week ago he quit when the police started searching the area. They took Valerie to force Frank to make one last run. If Frank doesn't make the run then they'll kill Valerie. Mac promises that they won't let it happen... because they're going to drive for Frank.
Jack and Mac pack the money into the minivan and Frank warns that they can't get arrested or they'll meet the rendezvous time. As they head out, mac calls Wilt and tells him to go to the band hall and make an antenna array for a radio direction-finding system. Wilt gets the antenna and rigs it on the roof with a music stand and a metal instrument. Riley uses it to hack into the police-band radios and figure out where they are so that their teammates can avoid the police roadblocks. There's a police car heading toward them, and Jack takes a side road to avoid them. Jack turns on the radio and continues driving.
The agents pass a police car and gives chase, and Mac figures that the officer had his radio off. Riley scrambles the officer's radio when he tries to call in, and Mac blows the hood and rigs the engine so that they can outrun their pursuer. They reach the rendezvous and spot Karl and his men waiting in another car. Jack tells Mac to get out because they're expecting one driver, and Mac grabs a can of spray before he goes.
Jack meets up with Karl and his men, and they bring Valerie out. Karl demands to know where Frank is, and Jack says that Frank couldn't make it but he brought the money. Karl tells him that they're going to hang onto Valerie to make sure Frank keeps driving for them. As they get the money, Mac sneaks up from the back and rigs the bad guy's car to explode. It does so and Jack, expecting something, takes on the thugs. Mac knocks out Karl, grabs Valerie, and tells Jack to tell Wilt to meet him at the lab as he runs off.
As night falls, Mac takes Valerie to the old treehouse that he and Wilt used as a lab. They climb up and Mac turns on the solar lights, and Mac assures Valerie that no one knows about I but him and Wilt. He explains that they built it after his mother died, and talks about how his whole world fell apart and he needed a place to put things back together again. The treehouse makes him feel safe, and that's why he brought Valerie there. Mac tells the girl to stay there while he makes sure the drug runners don't bother her and Frank again. He gives Valerie a homemade telescope to keep watch and assures her that everything will be okay, and gives her a whistle to blow if she needs him.
Jack follows Wilt's direction and pulls up in the minivan, and Mac joins him. They figure that they need to come up with a plan and Mac says that they'll give the drug runners what they want.
Later, Karl and his men find the empty minivan and start loading up the cash. Valerie watches through the telescope, while Jack and Mac run up and Mac dials Jack's cell phone that they put in the duffle bag. He sets of the same reaction he did in the lab earlier, and the crooks' car goes off the road. Wilt arrives with the police, including their friend Donnie Sanchez from school. Donnie insists on arresting Jack and Mac as well.
The next day, Patricia gets Jack and Mac released. She tells them to call her the next day something comes up, and Wilt asks Mac if he plans on coming back. He says that he plans to come back every year to talk to Arthur's science class, and Patricia says that Phoenix won't be paying the invoice for the minivan he wrecked. He asks to drive her rental SUV, and she reluctantly agrees. As they go, Jack and Riley asks what "The incident" was. Mac admits that they destroyed the football field with a nuclear meltdown.
Later, Mac takes Valerie back to the treehouse and tells her that it's all hers now. He makes her promise to come there often to expand her imagination; to be there for Frank; and to call him if her or Frank ever need anything or if she just wants to talk. Mac writes down his number on the back of a photo of him and Wilt as kids.
Written by Gadfly on Dec 10, 2016