Our heroes stop to visit their old friends Professor Juniper and Dr. Fennel on their way to Nimbasa City, just in time to witness an amazing event: Dr. Fennel uses a special Pokémon restoration machine to restore an Archen from a Plume Fossil!
The ancient Pokémon has some trouble adjusting to its modern environment, rejecting Cilan’s specially prepared food and complaining in an ear-splitting voice. Flying also proves difficult for Archen, even though it’s the ancestor of all Flying-type Pokémon. This gives our heroes and the researchers a monumental opportunity to witness the historic birth of Pokémon flight! At first Archen struggles to get off the ground, even with help from Ash’s Tranquill—but after it evolves into Archeops, it takes off easily!
Meanwhile, Dr. Fennel’s machine has drawn the attention of Team Rocket, who hack into it to steal the data. They also try to catch Archeops, but after losing a heated battle, they withdraw to celebrate their data-stealing success with Doctor Zager.
Worried about how Archeops will survive in the modern world, Dr. Fennel and Professor Juniper start making plans to create a proper environment for it...and then they discover the purpose of its persistent cries when three other Archeops appear! And so, united with others of its own kind, Archeops happily goes off with its new friends, and our heroes bid them a fond farewell.