This post is part of the series UK Blitz. Read from the start.

Wildeyed and hyperventilating, you turn terrified to face the lights racing down the tunnel. Thundering towards you swaying side to side like a loping predator, eyes blazing, comes a London Underground train. Mere inches separate the train from the walls of bolted steel rings but you knew that before you started. The train smashes through your body, cold steel unflinching as it drags you from your feet. For the briefest moment you are pressed against the glass, face to terror stricken face with the driver whose dreams you will haunt for the rest of his life. This won't worry you much longer however.

Gravity overcomes friction, then pulls your battered body down into the the rusty guillotine like wheels of the train which tear your limbs effortlessly from their sockets. Possessed by a glimmer of luck your spinal cord breaks, saving you the searing pain of your crushed ribcage for a second before 600 volts of direct current surges through whatever chunks of flesh are still connected. You have mentally scarred an innocent train driver and delayed the journey of thousands of londoners. This mess won't clean itself. However none of these things overly bother you right now, you have troubles enough with your pulped gibblets strewn along the tracks.

People will tell you it's too risky, too dangerous, it can't be done. Maybe it's these and more, but I entrust you to weigh the merits yourself. Do what you will with this information, pursuit of these adventures and spaces is an exercise left to the discretion of the reader. May I wish you the best of luck and god speed, you'll need haste a plenty when the rails sing, air rushes and blazing lights round the corner ahead.