Complex sentence: She opens the doors to the base so the shipment of runaways can be flown to the Partner, but before she can return to her companions she is telepathically knocked out by Miss Martian.
Split into simpler sentences: She opens the doors to the base so the shipment of runaways can be flown to the Partner. But before she can return to her companions, she is telepathically knocked out by Miss Martian.