This is one of the episodes in season 3 that introduces a new member
The pups get a distress call from a unknown rescuee, who turns out to be Ryder's long lost twin brother; Ranger! And now, a new member of D.E.M.I.S.E wants his head on a silver plater! Can the pups protect Ranger?!
(Title card with Monty and a skull mask on it)
Monty: Pups and the Sibling Rivalry!
(The epsode starts in D.E.M.I.S.E's Crystal Castle)