Middleverse

S1, E6: One day, Kurt's childish behavior clashes with Scott's dead seriousness once too often. Later, Kurt (in his true form) accidentally activates a device which transfers him to a parallel dimension. There, he meets Forge, who had been trapped there since the late seventies, and together, they devise a plan to break out and return to their normal dimension. Things get complicated when the other X-Men discover the device and the Brotherhood then tries to steal it from them.