Zack Underwood, a new kid in town, meets Milo Murphy, the unluckiest kid in town. Because of Milo's misfortune, he and Zack both miss the bus for school, so Milo shows Zack a "shortcut" to school, while attempting to avoid wolves, bees, fire, and even an alien abduction. Meanwhile, Melissa Chase, a friend of Milo's, collects lunches as wagers from other students on whether or not Milo and Zack will make it to school before the bell rings.
It's career day and Milo is having a hard time deciding what his career should be. He tries to decide while visiting the water works, fire department, and hospital. But of course, everything goes wrong. Meanwhile, Dakota and Cavendish try and make sure a shipment truck full of pistachios make it to the pistachio warehouse.
Milo and his friends visit a dude ranch. While horse back riding, they meet a girl named Jackie who joins their posse, and Zack is smitten with love. But, Jackie leads them into more danger than usual. Meanwhile, Sara is going crazy because the ranch reminds her of scenes from The Doctor Zone Files, and invites other fans to join in the geek fest.
Milo participates in a race and relies on Melissa and Zack to throw him reinforcements from his backpack to finish it. Meanwhile, Cavendish and Dakota, while attempting to stop the re-assigned Brick and Savannah from saving the pistachios, find themselves in the Old West and meeting Milo's great-great grandfather, Sheriff Murphy.
Milo, Cavendish, and Dakota travel to 1965 to help Orton Mahlson create The Doctor Zone Files. Unfortunately, they find that Derek, the son of King Pistashion, has somehow survived and has body snatched pretty much everyone, even in the present. In a cliffhanger, it turns out their sole hope lies in a particularly incompetent pharmacist.
Milo builds his own haunted house out of a decommissioned old truck and invites his friends to the fright fest, but Zack is not too amused because he's grown out of being scared on halloween, but thanks to Murphy's Law and the truck going on a wild ride throughout town, Zack slowly changes his mind. Meanwhile Dakota and Cavendish take in on the halloween fun while also investigating the mystery of the last halloween, which not surprisingly happens because of them, actually Dakota, and a wayward time grenade.