 The story's sequel, "Through the Gates of the Silver Key", presents Warren as an expert linguist who has mastered the primal Naacal language of the Himalayas.Lovecraft cowrote this latter work with E. Hoffmann Price; they collaborated on the piece from October 1932 to April 1933.What singles out Warren from Lovecraft's many other doomed characters is his self-sacrificial, gentle nature (he pleads with Carter to put back the crypt's slab and flee while he still has a chance to get away), combined with a sinister element that is more in keeping with Lovecraft's other ambiguous anti-heroes such as Richard Upton Pickman and Herbert West (Carter describes Warren's expression as "disquieting" when he talks about his occult theories).