It was eight in the morning, no-one had slept and everyone was coming down from a really good party. The kind where the number of lost wallets, drugs and phones amounts to a mini fortune for the hosts. The city hadn’t yet woken up – it was Sunday morning – so we found ourselves in that hazy limbo when all the station barriers are open. For a few hours, Lon-don is a different place: public transport is free and the trains are basically empty save a few exploited cleaners. I figured this was a good time to get out my virtual reality headset.