Moonlighting Season 1 Episode 5

Noted mystery writer J.B. Harland holds a writing contest each year. He then invites a few of his friends and the winner of the contest to try to solve a make-believe murder mystery aboard a moving train. This year, Agnes has won the contest, and Maddie and David accidentally end up with her on the "J. B. Harland Murder Train". But it turns into a real life murder mystery when J.B. turns up dead himself, and the mounting clues start to point to Agnes as the guilty party.