A new communications system causes problems at Cresta Cabs. Sam and Reen accidentally broadcast a private conversation to all cabs. Sam's partner Dexter returns from abroad after a breakdown caused by his unfaithful wife Tina.

Dexter sees the insurance salesman Tina had an affair with at his house. He jumps into the Thames, and soon afterwards the insurance salesman's body is found in the boot of one of the mini-cabs.