"What Sleeps Within the Cove" is the title of a fantasy romance novel by Harper L. Woods (a pseudonym used by Adelaide Forrest). It is the fourth book in the "Of Flesh & Bone" series. The story involves a character named Estrella who undertakes mythological trials in a Greek underworld-like setting to complete a dangerous mission. The narrative merges fae lore with Greek mythology and explores emotional growth and healing. In this context, "what sleeps within the cove" metaphorically refers to the story and its characters within the novel, rather than a literal entity or creature that sleeps within a specific cove. The novel itself is an adventure filled with magic, mythology, and romance. If you are asking about a literal or more poetic meaning of "what sleeps within the cove," it might depend on the specific source or context you are referring to, but based on the popular reference, it is the title and theme of this fantasy romance novel. Let me know if you want information on a different interpretation or source!