We thought it would be Fort Knox, but in reality an Oyster card really can work wonders to get into the Tube. And so we nervously opened a door into the system. The door was stiff and heavy, we didn't know if it would be alarmed, silent or otherwise. We checked around, and all looked good. So torches carefully on and covered, we stepped into the darkness. We could hear voices coming from below, and sat to watch for movement. We didn't see any signs of activity, and cautiously moved a torch down the wall of the shaft to see what was involved.

Figuring it was ok, we descended the caged ladder stairs down to the bottom of the vent. The voices were coming from the platform below the vent openings on the left in the pic below. It was somewhat creepy to hear people chatting away about things they thought were private, but we could hear every word. Sadly it was in some obscure East European language.

I carefully placed a camera in front of one of the grills, careful not to be seen. Although, I figured it unlikely anyone would be staring hard enough at the grill vents. The exposure means it's tricky to see the details of the platform, but the track edge can just be made out, and the name of the station.

There not being much to do and no access anywhere else, we turned and went back up the vent.

The night sky above giving us the cover we need to infiltrate the system.

At around 15mins, possibly the quickest dip into the system we've done. But when you're in the system, it feels good to be on top. 

Usual props to Kev.