Pokemon Season 14 - Episode 667 – A Night in the Nacrene City Museum

Ash, Iris, and Cilan arrive in Nacrene City and head to the museum where the Gym is located, but it is locked. A man runs out and introduces himself as Hawes, the museum's curator, and says that the museum is locked down because it is believed to be haunted. Cilan, however, states that he does not believe in ghosts, but Iris states it is possible. After the gang is given a tour, they are lead to a sarcophagus and a death mask believed to be linked to the Pokémon Yamask. As they prepare to camp out inside the museum to discover the truth, Team Rocket meets up with another contact in Unova who tells them they have to steal a meteorite from the Nacrene Museum. In the night, Iris wakes up the group to reveal that a strange haze is around them just as a medieval suit of armor attacks them. The ghost possesses several other museum displays, including a Dragonite skeleton, until the Yamask mask attaches itself to Cilan, taking over his body to state that it wants to leave. Just then, the museum's director and Nacrene City Gym Leader Lenora arrives and sends out her Watchog which uses its Illuminate Ability to disorient the Yamask, reuniting it with its mask which it lost when it was sleeping in the new museum artifacts; Hawes did not realize it was not part of the new shipment and included it in the displays. Once the mask was behind glass, the Yamask could not retrieve the mask on its own. Now with its mask, again, Yamask leaves the Nacrene City Museum and Ash tells Lenora he wants to challenge her for his second badge.