When his boss is killed, Detroit cop Alex Foley (Eddie Murphy) finds evidence that the murderer had ties to a California amusement park called Wonder World. Returning to Beverly Hills once more, Foley reunites with Detective Billy Rosewood (Judge Reinhold) to solve the case. Along with Billy's new partner, Jon Flint (Héctor Elizondo), they discover that the security force of Wonder World is actually part of a counterfeit money operation headed by park manager Orrin Sanderson (John Saxon).