Pokémon Adventures: Black and White Vol 6

From the VIZ Media edition

Team Plasma launches an all-out attack on the Nacrene Museum! What will they steal and who will they kidnap...? Black undergoes grueling training to prepare to fight the legendary Pokemon Zekrom. And White's new battle skills are put to the test! How did Black capture his first Pokemon... and who was it?

Source: Anime News Network Encyclopedia