Ben 10 Omniverse (Galactic Monsters) : An American Benwolf in London

Watch and Download Ben 10 Omniverse (Galactic Monsters) episode An American Benwolf in London. episode no. 44

Kai 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.

Source - wikipedia