“With air, you can struggle for a time. If you’ve trained in a Fish-Suit, you can struggle quite some time. However, without blood to your brain a few seconds is all it takes to become unconscious. Keep it up a few seconds more and that brief sleep can be extended by hours. A few more seconds and you can kill someone. It was all in the timing. Too little and they’d wake up whilst you were about your business. Too much and you’d kill them.”