Sunday Punch

A couple, the Franklins, arrive after a long journey, at his parents' home. They leave their sleeping son in the car while they go in to say they've arrived. Inside there is chaos and both Mr Franklin's parents are dead along with the dog. The son is distraught and accuses a neighbor of the murders because he hates the dog. The neighbor, Whitaker, said he heard nothing, but that they had had visitors the night before. He remembered a picture of a tiger on their car's bumper. Frank starts to investigate, starting with a mysterious empty envelope.