Everybody shivered. Poison gas was the oldest death for submariners, and the most feared. Bust a wall at the big depths and the pressure killed you before you even knew it. Slam! You’re pate. Fast and painless. They all knew the horror stories from World War Two back in the pre-Awakened days. Those old boats used nickel-lead batteries for power when they were under, and didn’t have reserve air to feed their massive diesel motors. If the hull got a leak and sea water hit the plates, it formed chlorine gas and whole crews died in screaming agony, skin bleached white as ghosts.