Uncle Buck is a charismatic hustler who has gotten by on his charm for years. But when his brother Will and sister-in-law Alexis move to town and need help with their kids, he steps up to become their nanny.

Alexis and Will try to help Maizy overcome her shyness in order to sell Sunny Scout cookies. When their plans for Maizy fail, Buck jumps in to help Maizy break out of her shell and hustle her way to the top.

Alexis rides along with Buck on his first day as a nanny, and he encounters a cranky principal, looks for a gluten-free snack and stages a minor break-in. Will tries to care for a sick Miles.

Buck finds common ground with Will's office buddies. Alexis drags her reluctant kids into a lip-sync battle.

Alexis is convinced that Buck is to blame for Miles' new, impulsive attitude after she catches him attempting a risky stunt for his YouTube channel. With Miles' punishment looming, Buck decides to throw a "going to jail party" while Mom and Dad are out, but a neighbor calls the cops and ruins their celebration.

Buck and his buddy Cy have a tradition of watching the Bulls games on TV together. But Buck's multi-tasking skills are pushed to the limit as Tia, Miles and Maizy all have separate crises on the night of a big game, and Will and Alexis are out celebrating their anniversary.