He took a last look around to make sure that the coast was clear, then gingerly crawled up the tiles towards the top of the roof. He used the chimneys to support himself as he went over the crest and slid down the other side on to a flat section of roof, which was set into the top of the building. There was a long, oval glass dome sticking up here and, crouching low so as to avoid making a silhouette against the night sky, James sneaked along until he was looking down into Codrose’s study. As often as not the housemaster would be sitting up here at night, writing in his journals with tiny, spidery lettering and drinking from a secret bottle of gin.

James pressed himself against the roof and sidled along, peering down through the murky glass. Sure enough Codrose was there. He was a thin man with a short beard that covered half his face and the cold, dead eyes of a fish. Many of the housemasters at Eton were well loved by the boys, but not Codrose. He was mean and joyless and served the worst food in the school.

James watched him for a while, scratching away with his pen, and wondered what he found to write about. It gave James a feeling of power to be up here, seeing but not being seen. He soon moved on, however. There were things to do.

When he reached the other end of the roof he climbed over the ridge and carefully slid down to a wide stone gutter. He walked along the gutter like a tightrope walker, holding his arms out for balance, until he reached the corner. This was the most dangerous part of the route: jumping across a narrow cobbled alleyway to the building on the other side. He looked down to make sure that there was nobody below, before shuffling back along the gutter to give himself a run-up. He took a deep breath, then raced to the end and hurled himself into the air at the last moment. He landed comfortably, kept up his momentum and continued running across a short flat roof, then leapt across another, smaller gap on the other side. This was James’s favourite part of the route, over several easy rooftops, running, jumping, climbing, until he finally arrived at a long, lead-lined gulley which led to the top of the final roof. He darted up it and squeezed between the chimneys, where he was stopped by a boy’s voice, hissing in the darkness.

‘Who is it?’

‘James Bond.’

‘Enter.’

The roof of this building was similar to the one at Codrose’s, with a flat section set into the top between the chimneys, but this was smaller and had nothing as grand as Codrose’s dome. Apart from a small inspection hatch in the middle, it was featureless. But it made a perfect hideout for a group of adventurous boys who called themselves the Danger Society.

There were many clubs at Eton – the Musical Society, the Film Society, the Natural History Society and the Archaeological Society, for instance. But the Danger Society was different. It was a secret society of boys who liked to take risks. If the Danger Society was ever discovered, its members would be in deep trouble.