Complex sentence: Perkins identifies the next likely victim to be Maisie, due to her trauma over losing her grandmother, and the Doctor tells Clara to bring her to the lab, having Gus unlock the storage door.
Split into simpler sentences: Perkins identifies the next likely victim to be Maisie, due to her trauma over losing her grandmother. The Doctor tells Clara to bring Maisie to the lab after obtaining Gus' permission to unlock the storage door.