Following Roland Deschain's confrontation with the man in black, the gunslinger descends from the Cyclopean Mountains to the Western Sea, where he is attacked by lobstrosities from the ocean. As his health wanes, he must travel the shoreline in search of three doors that will allow him access to Keystone Earth, from where he encounters people – including the drug-addict Eddie Dean, the schizophrenic Susannah Holmes, and the psychopathic Jack Mort – who are tied to his journey to the Dark Tower.