Magnum, P.I. (1980)

Higgins is driving visiting Pamela Bates - an old editor friend of Robin Master's - along with her friend, and her secretary, to the Estate, when someone tries to run them off the road and over a cliff. But Pamela insists on waiting for her own mainland investigator friend famous crime mystery writer Jessica Fletcher. The crossover continues on Murder, She Wrote S03E08 Magnum on Ice (II).