Originally built during the mid-20th century, Battersea Power Station comprised two halves – Battersea A and Battersea B. The building had been decommissioned some fifty years later and remained empty for some time, slowly falling to pieces.

Such a riverside site was far too valuable to waste, however, and was massively developed early in the 21st century, providing luxury accommodation, shops and entertainment centres, all of which were virtually bombed out of existence during the Civil Uprisings. The original structure, the power station itself, together with the former Chelsea Bridge – now Barricade Bridge – had formed the centre of the resistance and was the first to declare victory over the government forces.

Again, it had lain derelict for a very long time. The government, possibly wanting to avoid it achieving monument status but lacking the nerve to demolish it, had left it to decay until finally, just in time to prevent its complete collapse, the Time Police had moved in.

No attempt had been made to soften its stark and uncompromising exterior, and to this day it stood four square to the River Thames, reminding the world that time travel was still an offence punishable by death. If you were lucky.

Floodlighting the building had not made it any less sinister and it glowered out over the river. A major London landmark. Occasionally, and for reasons never afterwards explained to Commander Hay’s satisfaction, someone would attach a giant inflated pig to the dirigible tethering post.

The rooftop helipad was empty and likely to remain so. Commander Hay was known to dislike flying and the helicopter was used mostly by R&T, although how the sudden appearance of a black helicopter at a recruitment drive was supposed to encourage enlistment was a mystery to most. Popular opinion had it that Major Callen just liked flying in it.

The garden sloped right down to the river. This had been one of Commander Hay’s attempts to show the softer side of the Time Police, because flowers are, apparently, reassuring. The general public was encouraged to bring the kids, eat their sandwiches, grass up a family member or two and then take themselves off home, conscious of a job well done and a nice day out.

The two high-speed pursuit launches bobbed gently at their moorings. Flying might not be her favourite pastime, but it was well known Commander Hay had no objections at all to zipping dramatically up and down the Thames whenever the situation demanded.

Battersea A housed the working areas and Battersea B was mainly staff accommodation. Senior staff lived on the upper floors; dogs and lesser ranks on the ground floor. The windows stared balefully out over London. London tried not to blink.