It is Halloween. Lilo dresses up as a bloody gory character and Nani tries to get everything ready for when the trick-or-treaters arrive. But sadly, the house never gets any trick-or-treaters, a fact that Nani wants to change. Meanwhile, Experiment #300, Spooky, is activated. Experiment #300 can transform into anyone's greatest fear, and makes his way through the town frighening people. When Lilo finds out that #300 made its way to Kaiaulu Hale's Halloween party, she tells Stitch to go after it.