Dick Van Dyke's Medical Drama Brought In Star Trek Actors For An Alien Abduction Episode

"Diagnosis: Murder" blended medical drama with murder mystery, all with a lighthearted, tongue-in-cheek tone. The series' willingness to play with genre even saw it delve into the world of science fiction on occasion — and what better guest stars for an alien abduction episode than a line-up of "Star Trek" cast members?

"Diagnosis: Murder," which ran on CBS from 1993 to 2001, starred Dick Van Dyke as Dr. Mark Sloan and his real-life son, Barry Van Dyke, as police detective Steve Sloan. The Season 6 episode "Alienated" sees Steve take a fishing trip with his dad's young colleague, Jesse Travis (Charlie Schlatter), only for Jesse to go missing. Five days later, Jesse returns, believing that he's been abducted by aliens. This sparks an investigation involving several characters who'll look very familiar to "Star Trek" fans.

"Alienated" featured George Takei as a mysterious man in black; Walter Koenig as a crisis consultant who's later revealed to be a part of the alien conspiracy; and Grace Lee Whitney as another apparent alien abductee. Meanwhile, Wil Wheaton played Forest Ranger Gary Barton, and "Star Trek" franchise stalwart Majel Barrett appeared as the leader of an alien encounter support group.

In addition to the various "Star Trek" cast members who appeared in "Alienated," the episode also guest-starred Bill Mumy. Another major sci-fi alum, Mumy is perhaps best known for his roles in "Lost in Space" and "Babylon 5." Funnily enough, less than a month after his "Diagnosis: Murder" appearance, Mumy also joined the "Star Trek" universe in the "Deep Space Nine" episode "The Siege of AR-558." On "Diagnosis: Murder," Mumy played Parker Craddick, a man hunted by the same mysterious agents as Jesse.

With a cast of greats in hand, "Alienated" was happy to indulge itself as a straight-up sci-fi parody, as Jesse is pursued by ominous men in black and mysteries abound surrounding shady government facilities. In fact, although many of the stars had a history on "Star Trek," the episode feels more like an homage to "The X-Files" than anything else.

Ultimately, though, it would transpire that there were no aliens messing with Jesse on "Diagnosis: Murder." Instead, his abduction was the work of a pharmaceutical company trying to discredit him in order to protect their new drug's reputation. But while "Diagnosis: Murder" may not have veered into true sci-fi territory in the end, fans of classic sci-fi TV shows will no doubt get a kick out of the episode's array of guest stars.