Code of Honour (S07E06)
When two transient bikers are brought into the station for shoplifting, Tom is surprised to recognize one of them as Bull, an old friend from Vietnam. Unlike Tom, Bull chose a life on the open road with a different code and uniform. The biker lifestyle tempts Tom as he takes a ride on Bull's motorcycle, but Bull's carefree exterior hides a darker purpose—he's been searching for seven years for the man who murdered his daughter. Meanwhile, local video repairman Peter Ross is acting suspiciously since the bikers arrived, even assaulting Jack to end up in jail. It's revealed that Ross is the target of Bull's vendetta, as he is the ex who caused Bull's daughter's death. Tom and Bull find themselves in a tense standoff, refusing to leave until they get Ross.