Wyatt and Rufus are ready to get Lucy's sister back, but Lucy is missing. A bomb explodes at Mason Industries. Six weeks later, Wyatt survived the explosion but caught shrapnel in his back. He, Rufus, Jiya, Connor and Christopher have the Lifeboat, but are in hiding. Rufus, Jiya and Connor are working to fix the Lifeboat. Lucy is still missing, with Wyatt convinced she's alive but the others not so sure. Lucy has been pretending to go along with Rittenhouse until she can find a way to destroy the Mothership. Lucy and Carol take the Mothership back to World War I. They've gone back to save the life of Nicolas Keynes, Lucy's great-grandfather. Rufus gets the LIfeboat working and he and Wyatt go back to rescue Lucy. Emma shoots, then Lucy kills a soldier, to prove her loyalty to Rittenhouse. Emma needs an X-ray machine, so Carol and Lucy go to a nearby field hospital, where Marie Curie works. Curie agrees to go back with them. Lucy slips away to grab a hand grenade, then encounters Wyatt and Rufus. She sends them to blow up the Mothership. Jiya has another seizure. Wyatt and Rufus get caught trying to steal a truck. They are attacked by two Rittenhouse agents disguised as soldiers but Wyatt and Rufus defeat them, discovering a cell phone on one. The Mothership's radiation is interfering with the X-ray images. Lucy considers smothering the recovering soldier, but Carol catches her. The Curies find the Mothership. Lucy stands in front of them so Emma can't shoot them. Wyatt and Rufus interrupt them. Wyatt holds a gun on Keynes until Emma releases Lucy. Emma tells Lucy she will never get her sister back. Wyatt suggests Rittenhouse is setting up sleeper cells throughout history. Christopher retrieves Flynn to help them.