 Ninja Gaiden III : The Ancient Ship of Doom takes place between the events of the original Ninja Gaiden and Ninja Gaiden II : The Dark Sword of Chaos . The story opens with Irene Lew , one of the protagonists in the first two Ninja Gaiden titles , an agent for the Central Intelligence Agency on a mission called " Cardinal " . She gets chased to the edge of a cliff by a man who looks like Ryu Hayabusa , when the edge gives way , and Irene falls in the water to her apparent death . Ryu is accused of Irene 's murder but says it was not him , that it was somebody else who looked like him who tried to frame him . He first investigates a laboratory that Irene was investigating . After going through the laboratory , a mysterious man appears and tells Ryu to go the Castle Rock fortress , where he will give Ryu more information about Irene when he gets there . 
