An artefact in the Ashmolean Museum leads the Doctor and Bess to the ancient Egyptian port of Tamiat in the 12th century BC. The locals are raised with a healthy respect for the sea – for the wonders it can offer and the risks it can bring. But recently, more ships are going missing than usual, leaving no survivors. A new predator is lurking in the waves, attacking anything that crosses its path.
As Bess helps the young and impulsive Rabiah provide for her family, going on a perilous fishing trip that will take them to a mysterious island, the Doctor befriends concerned merchant Beku and annoys the wealthy Minhotep while trying to defend Tamiat against another menace: the Sea People, marauding pirates intent on stealing anything of value and destroying what’s left.
Surrounded by danger, the Doctor and Bess face overwhelming odds to protect not only the people of Tamiat from a deadly human threat but also the entire world from an alien species capable of dominating Earth’s food chain. The only hope lies in a desperate and treacherous act that could cost the Doctor his life.