Red Nails depicts Conan's greatest ever adventure as he goes deeper into the Jeweled City, where he is reunited with Valeria the pirate. Within the regions of the city, they meet the Princess Tascela who shows a very high amount of interest towards Conan's female companion Valeria, however its more than her body which the Princess lusts... Full of betrayal and against the darkest of sorcery, Conan must use his instincts to save those who he cares about against the influence of the lands most twisted evil.

This animated feature is based on the story written by Robert E. Howard of the same name published by the pulp magazine "Weird Tales" between July and October 1936. It was the last Conan story published by "Weird Tales" stories before Howard committed suicide in 1936 (four of his Conan stories were left unpublished, and would be published much later).