Rapunzel and the group are finally leaving Tirapai Island when the cargo ferry arrives, but Eugene and Maximus get into an argument, resulting in them falling overboard. However, they manage to save themselves on a passing ship, only to learn it is a prison ship where all the criminals have escaped and taken control. It also includes almost every enemy Eugene and the group have faced, including The Stabbington Brothers, Lady Caine and Axel. Eugene and Maximus attempt to escape, but discover the villains plot to ambush the cargo ferry and set out to stop them.
Meanwhile, Rapunzel and the gang discover Eugene and Maximus are missing and set out to rescue them. Eugene and Maximus argue on how to handle the situation until they are separated and captured. They are forced to walk the plank until Rapunzel and the group arrive in time to save them, leading to the criminals defeat. With the villains foiled, the group arrive safely back on the mainland and Eugene and Maximus reconcile, having come to respect and appreciate each other's different point of views.
- Mandy Moore as Rapunzel
- Zachary Levi as Flynn Rider
- Eden Espinosa as Cassandra
- James Monroe Iglehart as Lance Strongbow
- Jeff Ross as Hook Foot
- Paul F. Tompkins as Shorty
- Ron Perlman as The Stabbington Brothers
- Gideon Emery as Anthony the Weasel
- Laura Benanti as Lady Caine
- Artt Butler as Dale
- Jess Harnell as Pocket
- Kevin Michael Richardson as Otter and Ferry Captain
- Flula Borg as Alfons
- When Lady Caine reveals herself, her skull tattoo is on her right arm instead of her usual left.
- The German version of the title in English is "Danger on the High Seas".
- The Caravan, which was destroyed in "King Pascal", has been repaired.
- Corona's criminals, including Lady Caine, her thugs, Axel, The Stabbington Brothers, Dale aka the Fake Giovanni and Anthony the Weasel all return in this episode.
- Rapunzel and the group are revealed to have stayed on the island for six weeks.
- The first episode to have a title card.
- Moral: Always follow the rules when it comes to safety.