Cooper Ryland is second mate on the cargo ship, Marjorie Harlington, in Avonmouth loading for Bombay. He is surprised to learn that their ship owner, Sir Felix Harlington, will be sailing with them, bringing with him a party that includes his secretary and a chef, neither of whom are what they seem.
Sir Felix also brings valuable goods on board, including a painting with a black and tormented history. Ryland takes charge of two seemingly valuable cases which he puts under lock and key.
At the last-minute, their long-standing captain is replaced with the newly-promoted captain, Simon Winsly, a man of great ambition with a murky reputation. It is 1967 and trouble is brewing between Egypt and Israel, threatening their passage through the Suez Canal. A sense of unease is felt by the crew as they get underway.
Harlington Ocean Lines is a family-held concern with roots and connections going back to the time of the British Raj. Sir Felix is on a mission to end an ancient family feud, which sets a wealthy Indian family against his own. This provides the backdrop of mystery as dark deeds unfold.
Who was Marjorie Harlington, the woman after whom the ship is named? Why does no one in the Harlington family wish to discuss her? Where did she disappear to all those years ago and what has she got to do with the mysterious painting?