Magnum, P.I. - Season 4 Episode 4 Distant Relative

Under protest, Thomas agrees to chaperone Rick's visiting 22-year-old sister Wendy while Rick works at the club, and quickly discovers that she's not the convent school innocent her brother thinks she is; after Wendy gives him the slip, Thomas scours the city searching for her and is devastated when the police find her murdered in an alley; when Rick blames Wendy's death on Thomas, the relationship between the men is dealt a severe blow, and Thomas vows to find her killers, even though Rick is determined to do the job himself with the help of information and an Uzi provided by Ice Pick; Thomas and T.C. follow Rick to Molokai, where the murderers are killed in a fiery crash as they are pursued by the three friends; to spare Rick's feelings and ease his grief, Thomas tells his friend the convincing lie that Wendy was a good kid who was just in the wrong place in the wrong time, instead of the truth that she was a drug mule murdered by the men for whom she worked.