The novel is presented as the transcribed testimony of Jessop, who we ultimately discover is the only survivor of the final voyage of the Mortzestus, having been rescued from drowning by the crew of the passing Sangier.

"The Ghost Pirates . . . is a powerful account of a doomed and haunted ship on its last voyage, and of the terrible sea-devils (of quasi-human aspect, and perhaps the spirits of bygone buccaneers) that besiege it and finally drag it down to an unknown fate. With its command of maritime knowledge, and its clever selection of hints and incidents suggestive of latent horrors in nature, this book at times reaches enviable peaks of power." — H.P. Lovecraft