Mac and a bounty hunter join forces with a bulldog named Frog to track down a Bulgarian defector who was the accidental witness at a murder and who is now being stalked by the killer, who needs a map she doesn't know she possesses.

Mac's old friends, the bounty-hunting Colton brothers try to find a young woman who's the only witness to a Chinatown murder, aided by their wise and patient mother, their impatient younger brother and their dog, Frog.