At the abbey, Sister Amy makes a bargain for immortality; and in the woods, the race to find the Bleeding Tree intensifies now that Kyle is infected.

The Navy prepare to implement Plan B, a final solution to ensure that the virus and everyone infected with it never make it off the island.

Kyle and Jordan attempt to flee the island, but their escape is made more difficult by the followers who are hunting them down; Walker and Alan plan to halt ILARIA's deadly plan as soon as they find the Mother Tree.