Randall and Hopkirk (Deceased) (1969)

S1E10 When did You Start to Stop Seeing Things?

A corporation enlists Jeff to uncover the source of a stock market leak. However, as Marty notices Jeff's unusual behavior and suddenly realizes he can’t see him, he discovers that the genuine Jeff has been kidnapped. The impostor, masquerading as Jeff, is using this guise to carry out a series of murders targeting financial professionals. In a bid to rescue the real Jeff and stop the chaos, Marty seeks the help of a hypnotist to turn the tide.