In the midst of high school chaos, Jake and Wendall are deeply invested in their mission to secure a date for Jake with the mysterious Angie. An invitation to a party appears to be their ticket to romantic bliss, but their plan is thwarted by an unexpected twist: Jake's parents have scheduled a dinner with Grandpa Lou, an event that promises to be a tedious ordeal. Grandpa Lou, played by James Caan, is a retired intelligence officer obsessed with sharing dubious war stories and delving into paranoia-driven conspiracy theories, perceiving the world as fraught with danger.
Unbeknownst to Jake, Angie’s situation deteriorates drastically when she is abducted by General Komencho, a Russian operative. Grandpa Lou possesses secrets of his own that could change everything. Despite being a former intelligence agent, he finds himself stymied by bureaucratic obstacles when seeking official support. Instead, he turns to his eclectic old contacts and enlists the help of his crew—comprising Wolf, Harry, Mother, and Giovani—who are collectively known as the 'Devil's Scum.' Together, they initiate a daring rescue operation.
As Jake and Grandpa Lou form a surprising alliance, they employ Wendall's tech expertise to outsmart their adversaries. The journey is filled with humorous one-liners and comedic blunders that encapsulate the dynamic between the young and older generations.
Ultimately, Grandpa Lou's team succeeds in rescuing Angie, just as government agents led by Maddy Harcourt arrive on the scene. In a dramatic moment, Grandpa Lou's health falters, leading to a hospital visit that adds a layer of suspense to the narrative.
The plot takes a poignant turn during Grandpa Lou’s funeral, where family and friends gather to honor his memory. Jake grapples with his loss, receiving Grandpa Lou's dog tags from the elderly attendees, serving as a symbol of the passing of responsibility from one generation to the next.
However, a month later, an unexpected turn of events occurs when a car stops in front of Jake’s house. From it emerges Grandpa Lou, revealing that his supposed death was merely an elaborate ruse, a cover-up for his retirement. Jake watches as Grandpa Lou and Maddy Harcourt drive off into a new life of adventures in Mexico, leaving him to reflect on the complex themes of family, loyalty, and the intricacies of deception.
