The kingdom of Thundera has been attacked by an army of Lizard people. Lion-O and the Thundercats are set on a quest to obtain the Book of Omens to help restore their kingdom's peace. The team will have to face numerous villians that stand in their way including Mumm-Ra & Slythe. With the Sword of Omens in Lion-O's pocession, he'll be able to use it's powers to fight off the evil that stands before him on his quest.