Magnum, P.I. - Season 6 Episode 12
I Never Wanted to Go to France, Anyway...

An old comrade of Higgins brings his travelling carnival to Hawaii. But when one of the performers is fatally stabbed, Higgins asks Thomas to investigate. Working undercover as a carnival roustabout, aided by Rick, Thomas learns that even before the killing, the carnival had been experiencing a string of accidents, and must pin-point exactly who is trying to force the show out of business...