The show's format and tone drew comparisons to NBC's Night Gallery and ABC's The Sixth Sense.

The series was hosted by Sebastian Cabot as Winston Essex, the owner of a mysterious hotel called Mansfield House.

[5] Starting with the 14th episode when the show was retitled Circle of Fear, Cabot's introduction and ending monologues are no longer featured.

Guest stars included Helen Hayes, Jason Robards, Patricia Neal, William Windom, Gena Rowlands, Carolyn Jones, Melvyn Douglas, Stella Stevens, Tyne Daly, David Soul, Karen Black and Jodie Foster.

[7] D.C. Fontana scripted the episode "Earth, Air, Fire and Water", based on a story by herself and Harlan Ellison.