The science fiction TV movie-of-the-week Man From Atlantis IV: The Disappearances airs on NBC, starring Patrick Duffy and Belinda J. Montgomery. Ernie Hudson (Ghostbusters) guest stars. Man From Atlantis will continue as a weekly series in the fall 1977 season. 
The Foundation prepares for a visit from a wealthy lawyer who has expressed an interest in donating a boat, but their benefactor is very specific in wanting Dr. Merrill to personally inspect the boat. This is a ruse to lure her away from her comrades and kidnap her; she is taken to a remote island compound where Dr. Mary Smith is hatching a scheme to create a special water treatment robbing her subjects of all willpower, and to then launch a rocket to colonize another planet with this obedient population. Mark, impervious to the treated water which overcomes its victims’ minds on touch, must rescue both Dr. Merrill and Dr. Simon and thwart the plan.
teleplay by Walter Murdoch
story by Jerry Sohl
directed by Charles S. Dubin
music by Fred Karlin
Cast: Patrick Duffy (Mark Harris), Belinda J. Montgomery (Dr. Elizabeth Merrill), Kenneth Tigar (Dr. Miller Simon), Alan Fudge (C.W. Crawford), Darleen Carr (Dr. Mary Smith), Dennis Redfield (Dick Redstone), Pamela Peters Solow (Jane), Fred Beir (Sub Captain Bracey), Paul Mantee (Cetacean Crew), Michael Jay London (Cetacean Crew), Arthur Batanides (Cetacean Crew), Rick Goldman (Cetacean Crew), Bob Minor (Minion), Ric Drasin (Minion), Frank Martone (Minion), James Fraracci (Minion), Jim Morris (Minion), Ernie Hudson (Minion), Anthony Pearson (Minion), Julius Le Flore (Minion), Jim Tarleton (Minion)
Notes: Yes, that’s future Ghostbuster Ernie Hudson in a “strong man” bit part, one of his earliest professional acting appearances. This marks the final appearance of Kenneth Tigar as Dr. Miller Simon, a character who vanished in the sweeping changes that take place between the four Man From Atlantis TV movies and the already-greenlit weekly series.
LogBook entry by Earl Green