2x21 - Codename: Kids Next Door

The KND take a vacation to the beach (and Numbuh 1 promptly leaves, since he hates the place), where Numbuh 3 is quickly kidnapped by the armored Kinights of the Round Towel, who drag her before King Sandy, a miniature monarch who quickly falls in love with her! Naturally, the concerned Numbuhs 4 with Numbuhs 2 and 5 confronting the beachcombing brat in his enormous sandcastle... but they are soon overwhelmed. Can the KND topple this tiny tyrant before high tide?