While delivering a pirate ship to Museum Station, the Mighty Express finds a treasure map that leads to a legendary train pirate's secret cave.

Nate must transport a giant castle the kids and trains of Tracksville need for the Medieval Festival, but Tricky Ricky and Sneaky Sally want the castle and crown for themselves.

Faye must deliver a bathtub car to Farm Station so Bart can take a bath, but Bart doesn't want to take a bath and causes problems for Faye.