Iron Mike (a.k.a. Captain Mike Ferguson) - S2.E12

The crime-busting pair's suspicions are aroused when they spot highly respected Police Captain "Iron Mike" Ferguson accepting an envelope from an underworld kingpin. When Ferguson recruits the duo to aid on a stakeout, they learn that he is receiving tip-offs about various criminal activities in return for ignoring and covering for the crime kingpin's operations. It's resulting in getting a number of criminal organisations off the streets, but it means that Ferguson is ultimately a corrupt officer, and the pair are torn what to do...