The episode starts with Ash and co. seeing Sanpei and his Greninja floating down a river.
Ash helps them out of the river and back onto land.
Ash then uses his Pokedex on Greninja.
He realises that it has evolved from when it was a Frogadier.
A stream of water then shows up near the group.
After the water disappears, a ninja wearing a Shiftry mask and his Barbaracle reveal themselves.
Ash's Froakie tries to attack the Barbaracle, but it loses pretty quickly.
I think the man in the Shiftry mask disappears again.
Ash and co. (including Sanpei and his Greninja) are now in a forest.
There is a flashback to when Sanpei and his Greninja battled the masked man and his Barbaracle.
Sanpei lost the battle and he and Greninja fell into the river.
Clemont shows off a new invention.
The invention is a set of target practice boards, that look like the whole group.
Team Rocket are walking through a forest and come across Clemont's invention.
One of them kicks it and then it explodes.
They are all on the ground, hurt from the explosion.
Dare Da? Barbaracle.
Ash and co. are walking along a wooden ledge along a cliff, with Froakie and Greninja.
Clemont is crawling and eventually falls and then Serena falls too.
They are saved by Froakie and I think Greninja too, I'm not sure. I only saw Froakie saving Clemont.
The group then goes into a cave that is full of Goldbat that start to attack them.
Greninja then uses Smokescreen to let the group escape, which they do.
One of the Air Slash attacks almost hits Clemont.
The group are outside of the cave now and then the masked ninja and his Barbaracle show up.
Ash and Sanpei use their Froakie and Greninja to attack Barbaracle.
Froakie and Greninja both use Double Team I think.
Pikachu also helps out.
Team Rocket eventually blast off and then the Ash and Sanpe continue to battle the masked ninja.
Ash's Froakie is trapped under a pile of rocks and Barbaracle comes towards him with Poison Jab.
Froakie then evolves into Frogadier with a big blue explosion and it is now freed.
Frogadier battles Barbaracle and uses Aerial Ace and does quite well.
The masked ninja and Barbaracle then disappear as leaves circle around them in a tornado fashion.
As the sun sets, the masked ninja and Barbaracle appear again in front of Ash and co.
We learn that the masked ninja protected Clemont inside that cave.
Serena, Clemont and Bonnie are really happy with Frogadier and he then gets embarrassed.
The episode ends with a shot of Frogadier and Greninja.
To be continued.
Team Rocket show up also and try to capture some Pokemon.