Episode Title:Shell Shocked: Part 1.Episode Description:After months of planning, Hiccup has come up with a fool-proof plan to defeat Viggo once and for all and finally reclaim the Dragon Eye. The riders and their allies storm his base, only to find it in ruins along with an injured Viggo. He reveals that Ryker has taken charge of the Hunters and offers to surrender the Dragon Eye in return for Hiccup's help in stopping Ryker, but escapes during an attack on the Defenders of the Wing, leaving the riders with the baby Eruptodon in their care. When the riders find Ryker, he tells them that Viggo is setting them up and he can give them the Dragon Eye as the Berserkers are attacked by the Shell Fire, a giant sea dragon equipped with Hunter weaponry. Just as Hiccup is left without any ideas on what to do, who to trust, or even how to handle his developing feelings for Astrid in the midst of growing danger, Viggo returns and offers the Dragon Eye as proof of his word and offers an equal alliance to bring Ryker down.