The Deepest Kind of Sleep Beneath

With another crew member down and the sub malfunctioning, Sue tries to trigger an automatic ascent and bring the sub back to the surface despite the raging weather conditions. Simon becomes increasingly focused on securing the artifacts and subsequently puts the whole mission at risk in order to obtain them. Kate finds herself in a precarious position in navigating Simon’s volatile state of mind. Meanwhile on the Mosby, someone aboard has caused near irreparable repair to the engine, while Sue investigates, Caleb assists Kate via the radio.