Out of Time's Abyss is an Edgar Rice Burroughs science fiction novel, the third of his Caspak trilogy. The sequence was first published in Blue Book Magazine as a three-part serial in the issues for September, October and November 1918, with Out of Time's Abyss forming the third installment. The complete trilogy was later combined for publication in book form in 1924 under the title The Land That Time Forgot, which is also the title of the first novel in the series.

Out of Time's Abyss is a direct sequel to The Land That Time Forgot and The People That Time Forgot and continues the lost world saga begun in the earlier stories.

Out of Time's Abyss tells the story of Bradley, who was the second-in-command of the British tugboat that rescued Bowen Tyler and Lys La Rue in The Land That Time Forgot. Bradley became Bowen's second-in-command of the captured German submarine U-33 which took them to the island of Caspak. Bradley disappeared on an expedition in The Land That Time Forgot, and Out of Time's Abyss follows his later adventures on the island of Caspak. He meets Co-Tan, a native woman, and together they face various perils before ultimately meeting up with the other characters from the first two novels..

Edgar Rice Burroughs (September 1, 1875 -- March 19, 1950) was an American author, best known for his creation of the jungle hero Tarzan, although he produced works in many genres. Burroughs wrote popular science fiction stories involving Earthly adventurers transported to various planets, notably Barsoom, Burroughs' fictional name for Mars, and Amtor, his fictional name for Venus, as well as lost islands, and the interior of the earth in his Pellucidar stories. He also wrote westerns and historical romances.

• Chapter 1
• Chapter 2
• Chapter 3
• Chapter 4
• Chapter 5

The Caspak trilogy

• The Land That Time Forgot
• The People That Time Forgot
• Out of Time's Abyss