Dean convinces "Castiel", who is still Lucifer, to send him back in time to the last reported sighting of the Hand of God which could be useful as a weapon against Amara. Lucifer sees the potential in getting his hands on this weapon so goes along with it and sends Dean to 1944 to the fated submarine mission that sunk the Hand of God. Meanwhile, continuing his charade with Sam while they wait for Dean's return, Lucifer plans his next move.