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 under the
title of The Land That Time Forgot (properly speaking the title of the first
part) by A. C. McClurg in June 1924. Beginning with the Ace Books editions of
the 1960s, the three segments have usually been issued as separate short
novels. The third of these is treated in this article.
Out of Time's Abyss is a direct sequel to The Land That Time Forgot and The
People That Time Forgot, continuing the lost world saga begun in the earlier
stories. It connects the previous two installments, bringing in characters
introduced in each. Burroughs completes the revelation of his lost world's
unique biological system, only hinted at in the previous installment, in which
the slow progress of evolution in the world outside is recapitulated as a
matter of individual metamorphosis. This system forms a thematic element
serving to unite the three otherwise rather loosely linked Caspak stories.