While fiddling with the time capsule, Lion-O somehow finds himself sent to the past, before Thundera was destroyed. Meanwhile, the Mutants attack Cats Lair with a seemingly invincible robot.
Tropes:
- An Aesop: "No one can change history. We can only learn from it."
- Contrived Coincidence: The robot isn't the reason Lion-O returns to pre-destruction Thundera but he still ends up being given the way to defeat it.Claudius: It may prove useful in another world, another time.
- Irony: The robot was defeated, thanks to the plans Lion-O obtained from Claudius who stole it from the Mutants, which is what Slythe and Vultureman were trying to retrieve.Vulture: Even if the old fool has the plans, it will perish with him!
- Magic Versus Science: Mumm-Ra sees the robot's defeat as evidence it'll take magic instead of science to defeat the ThunderCats.
- Mistaken for an Imposter: When Lion-O runs into two guards who asks who he is, he declares himself "Lion-O, Lord of the ThunderCats". They tell him Claudius is the true lord, Lion-O tells him he's Cladius' son, but they know he's a boy, so they assume adult Lion-O is a Plundarian spy. Lion-O has no time to explain and demands that they let him pass or he'll use his sword, but they noticed it's the Sword of Omens, so they allow him to enter the city while also warning him he might not make it back out due to the earthquakes.
- Never the Selves Shall Meet: Averted, as Lion-O merely watched his younger self and the other ThunderCats from afar as they board the spaceship.
- Scary Scorpions: After being teleported back to Thundera, Lion-O comes across a giant desert scorpion. He fight it briefly until it falls into a large crack caused by an earthquake.
- The Worf Barrage: Cat's Lair uses a bunch of powerful weapons never seen before to attack the warbot, just to establish their only hope is to Attack Its Weak Point.
