Jackie has been dead since Yellowjackets season 1, but she’s continued to appear since then, and a new trailer has confirmed that Ella Purnell will still be in the show for season 3. Throughout its run, Yellowjackets has ingeniously used its dual timelines to foreshadow major plot events. In season 1, the most shocking use of this technique was teasing Jackie’s dark fate. Jackie didn’t have an adult counterpart in the present-day timeline, so it was obvious that something terrible would happen to her in the ‘90s timeline — but it wasn’t clear what.

In the season 1 finale, Jackie got into a big fight with Shauna and was ordered to sleep outside the cabin. However, the next morning, much to Shauna’s horror, they found that it had snowed throughout the night and Jackie had frozen to death. Jackie’s death caused immense guilt for Shauna throughout season 2, since she was technically responsible,...