After being injured by Team Plasma's attack, N falls unconscious, and Anthea & Concordia appear and take N away to a lake where N starts to heal. Cautious about Ash and co.'s presence, Anthea & Concordia explain that the area is a special place where Pokemon and humans come to be healed of their wounds and to live in peace and this is where N lives, except that none of the Pokemon trust Ash and co. at all because of what Team Plamsa did to them was terrible, and there some kinds of people who are impressing their powers in the outside world. That is why Anthea & Concordia accuse all people of being bad without even believing that not all people are bad enough just once. Giving the history of the area, Ash and his friends learn of N's past and how he is connected with Team Plasma and Ghetsis and how he met Reshiram. However, when Team Plasma finds the place and attacks, Anthea & Concordia accuse Ash and his friends of assisting Team Plasma to find the area, but they're not with them at all as they change their mind when they see them try to protect it from Team Plasma. Will they succeed and earn the trust?
All of the secrets came out when N was Team Plasma's greatest leader that Ghetsis wants him to be, with his ability to hear the inner voices of Pokemons but, all of his words are nothing but lies when Ghetsis used Anthea & Concordia to create a diversion in his plan instead to bring Reshiram's wrath. That explains why N and Team Plasma know each other when they found him from the last episode.
In the flashback, it is revealed that N met Reshiram when he's with Ghetsis the whole time during the ceremony when Reshiram burned the whole building to ashes. That explains why he had a bad memory in the first place without telling Ash and co. anything when they first met.
It is also revealed that N, Anthea & Concordia witness the terrible experiments that Team Plasma has done in the outside world using their machines to manipulate Pokemons in order to use them as weapons. That also explains the reason why they were rescuing Pokemons from them when they've been taken refuge from Team Plasma. Like N rescuing Braviary once in BW116: Saving Braviary.