Edward Marston; Murder on the Oceanic; Ocean Liner Mysteries; Oceanic; Edwardian mystery; historical mystery; historical crime; maritime mystery; ocean liner murder; shipboard mystery; detective fiction; British detective; murder investigation; whodunnit; period crime fiction; cozy historical mystery; nautical suspense; luxury liner; early twentieth century; Book 7; mystery series; British crime fiction; historical detective; sea voyage mystery; passenger liner mystery; historical suspense; vintage mystery; maritime crime; Edwardian Britain; historical whodunit