"Mermaids 13" is a novel by John L. French that was published in 2019. The book tells the story of Captain Natalya "Nat" Shikerova, a member of the Russian Navy's special operations team. Nat and her team are tasked with investigating a mysterious and deadly incident aboard a US Navy submarine that appears to be linked to a series of other maritime disasters around the world. As they delve deeper into the investigation, Nat and her team uncover a sinister plot involving a secret society of mermaids and a powerful ancient artifact that could threaten the entire world. With time running out, Nat and her team must race against the clock to stop the mermaids and prevent a global catastrophe. "Mermaids 13" is a thrilling and action-packed adventure that blends elements of science fiction, fantasy, and military fiction into a unique and entertaining tale.