You open the door, and you immediately realise that there’s something wrong. You can hear running water. Not just a dribble, but a full-on torrent. You look down, and you realise that the bottom of the stairwell is a couple of feet deep in milky-brown water. You stare at it for a moment, and then run down the stairs, stopping at the water’s edge. The last few steps have simply disappeared under the encroaching water. It doesn’t look that deep. Knee height at most. But you’re going to get seriously wet if you go in after Davy. It might even be dangerous for you.