It turned out one of them had brazenly walked down the road to Sigma and turned left sharpish into the derelict Pyestock site when he realised there were cars parked outside. "I didn’t even know there were active buildings here" he explained. However, I suddenly realised this was the guy we’d seen and so hurriedly hid to avoid. Laughs all round. Did they know where the plane was? Or the Power Station? No, they were new to the site. We exchanged farewells and pushed on.

The mass of pipes emerging from the Air House was our next target. Whilst we worked well in pairs, it appeared our triple was a little less organised and we all disappeared into the maze of blue pipework individually. Not for the last time keeping our little team together was like herding cats.