On a ship, a mysterious woman sunbathing captures the attention of the male crew. Miss Katherine Laker's questions make the crew suspicious. Peter is surprised to see her. The crew learn that Katherine is replacing Wally as Chief Purser.
Initially, the crew harbors resentment toward Katherine Laker, but opinions gradually shift. Peter confronts his ex-stepmother Katherine. An unexpected visit from Katherine's estranged father, George Terson, reveals their strained history.
Katherine Laker and Arthur Parker engage in a tense confrontation in his office. Later, Arthur seeks a reason to dismiss Katherine from her job as Chief Purser, while Wally bonds with Katherine.
An argument between Katherine and Peter escalates, resulting in her slapping him. Wally is found in a coma and is airlifted off the ship to the nearest hospital. Peter's request for time off leads to another confrontation with Katherine.
Sandy takes a spiteful jab at Katherine regarding Peter. Despite orders to remain on board, Peter has left the ship. Katherine's friend, Jeremy Gates, pays her a visit, arousing Matt's curiosity. Peter is found injured on the ship.
Wally receives a visitor during his hospital recovery. Arthur and his secretary Sophie conspire to have Katherine fired. Linda, a prankster and former crew member has returned to work on the ship. Linda meets Katherine for the first time.