'In the far wall was a door; on it, FIRE EXIT with a picture of a running man and an arrow, and PLEASE SHUT GATE. This door only opened one way. I went through, and wedged it ajar with one of the bricks. Beyond, stairs led to a rectangular lake, houses with glass balconies, and another one-way gate. I left that unlocked too, using the second brick. I didn’t expect to need this escape route. Time to go.'