Anthology series featuring mystery and supernatural stories hosted by Orson Welles. In the US, the series was broadcast as "Great Mysteries". A mysterious and spellbinding musical theme by John Barry accompanied with a blurred and shady filmed sequence showing a silhouette which moved at a slower pace toward the camera marked the beginning of this anthology series.
Then, a close-up of cigar billows and the words "Here’s Orson Welles ". Later Orson Welles appeared wearing a wide black cloak and a broad-edged Fedora . Pulling aside the cigar, Welles introduced the day's episode and its cast.
The episodes showed situations of mystery and intrigue that could be contemporary or historical. Sometimes, they paid tribute to Edgar Allan Poe, as the episode of the deceived husband who seeks revenge to clean his honour. Some stories were funny, as in the episode where a young man is invited to introduce his wife in a formal dinner at his boss' house, but she proceeds to embarrass him about everything in the course of dinner. Yet the mysterious and strange usually formed the plot of the most part of episodes, just like the story of the ambidextrous man who is forced at gunpoint to write two letters of suicide each with a different hand, compelling his murderer to choose which of the two letters he will leave near his victim.