The body of a young bride is found hung over the side of the S.S. Water Glide. Private and Twilight are sent to investigate her death right when she was announced to be engaged to a young prince. Things are hardly as they seem when a pony from Private's past makes her appearance. While investigating Private falls overboard in a terrible storm and is saved by a forgotten race of ponies, dubbed Seaponies. The lost tribe is in search of one of their own who left them. The twist? She left because she fell in love with the very same prince who's bride was murdered. Was she responsible? Or are there darker forces at work here?