Steve Martin and Bonnie Hunt return as heads of the Baker family who, while on vacation, find themselves in competition with a rival family of eight children, headed by Eugene Levy,

Disgraced Navy SEAL Shane Wolfe is handed a new assignment: Protect the five Plummer kids from enemies of their recently deceased father — a government scientist whose top-secret experiment remains hidden in the kids’ house.

The Baker brood moves to Chicago after patriarch Tom gets a job coaching football at Northwestern University, forcing his writer wife, Mary, and the couple’s 12 children to make a major adjustment. The transition works well until work demands pull the parents away from home, leaving the kids bored — and increasingly mischievous.