Murdoch and Inspector Brackenreid are aboard the SS Keewatin after the owner, Clarence MacFarlane, receives what he believes is a threat. The Keewatin is about to depart from Toronto on its maiden voyage destined for Rochester, N.Y. and Murdoch thinks they should stay on board, especially after he sees that Julia is one of the invited guests. Their presence proves useful after MacFarlane's daughter Amy, who is engaged to her father's chief financial officer Owen Mathers, falls overboard and is nowhere to be found. As Murdoch investigates he finds there is a real threat against the Keewatin and the true facts behind Amy's disappearance.
