I am one the few people who know the secret of the fifth floor of the British Library.

If ever lost in this august building, you should come to this level and turn left along the balcony above the reading room.

At the far end you will find the old-fashioned lift, operated by a pale young man. Climb into the lift, ask for the ground floor, be prepared for your ears to pop, and enjoy the journey downwards and back out into the open again.