After many years, Ferris and Tirtouga are reunited, though in unexpected circumstances after they save him from the wild Whirlipedes Tirtouga disturbed. What's more, Team Rocket still need Tirtouga's life energy but now it evolved into Carracosta to stabilize a space-time warp below Twist Mountain to the past called "The Time Gate". Can Ash and co. stop their latest plot to gain control in the past from happening?
This is the only episode when Ash looked up on two Ancient Pokemons Tirtouga and Carracosta on the Pokedex other than Archen and Archeops in BW039: Archeops In The Modern World!
Ash and co. may have seen one Whirlipede with Burgh in BW025: Battling For The Love of Bug-Types! but this is worst when all three of them are wild and aggressive.
This is the second time an Ancient Pokemon's food never exists in today's modern world when Ash and co. fed it. First was BW039: Archeops In The Modern World! when they feed Archen with Pokemon food.
Who's that Pokemon?: Carracosta (US).