Ben 10: Omniverse - An American Benwolf in London

Seizoen: 5 - Aflevering: 4 / 106 - Eerst uitgezonden: 08 maart 2014 - Episode ID: 940776

Ben's childhood crush, Kai Green, asks Ben and Rook for help when her grandfather is kidnapped by the Forever Knights who are after a mysterious sword all the way in London hidden in a secret room under the river. Could what the knights seek be King Arthur's mythical blade, Excalibur?