Pokémon Adventures: Black and White Vol 7

From the VIZ Media edition

Black trains hard to prepare to rescue the Gym Leaders from Team Plasma's clutches. Then he tries to convince a group of embittered Pokemon to trust humans again, while Trainer Alder tries to convince Team Plasma's King N that hte Pokemon League exemplifies the powerful bond between Pokemon and Trainer. Now, will Black be able to enter the Pokemon League and fulfill his dream? And if so... will he win? And will Black and White ever be together again?

Source: Anime News Network Encyclopedia