Randall and Hopkirk (Deceased) (1969)

S1E1 My Late Lamented Friend and Partner

In the opening episode, Marty Hopkirk is killed by a client's spouse, but he doesn't rest in peace. Instead, he comes back as a spirit to assist his friend Jeff in uncovering the truth and bringing the murderer to justice. Together, they navigate the challenges of solving the crime, as Jeff learns to embrace Marty's spectral presence in their quest for retribution.