Magnum P.I. Season 3 Episode 4 First the Beatdown, Then the Blowback ( Air Date 2021-01-08 ) Genre Action & Adventure, Drama, Crime category. Overview "Magnum and Higgins help an up-and-coming mixed martial arts fighter who is being pressured by a gang to throw an illegal fight. Also, Kumu is arrested for stealing an artifact from a collector that should be returned to its original resting place.".