Doctor How and the Deadly Anemones by Mark Speed

century security had tightened. Roddy had been caught and received a caution for trespassing. Although they styled themselves as hip and edgy, a criminal conviction could exclude them from some contracts so they’d decided to have a look around for something else.
    They’d found a website about the capital’s secret underground world – unused Tube stations, sewers and lost rivers. The stations had been interesting but security was always being tightened. After a court appearance and a fine, they’d decided to concentrate on the lost rivers. The equipment was inexpensive – boots, waterproof trousers, flashlights and caving helmets. The advice on the website had been for a minimum of three in a party, but Roddy and Steve had always believed in keeping the numbers down because it made for more agility. That, and the fact that they didn’t know anyone else who was into this sort of thing.
    South London had been perfect because of the more extensive river systems within the network, and for the fact that it was, well, South London; the authorities cared little for anything on that side of the Thames. The lower population density also meant less sewage and, if you followed the rivers, it was a relatively clean experience. There was no pressure down there – not even the light of day – and they’d often taken up to twelve hours carefully mapping out the labyrinth of tunnels. If you knew your way you could pop out under cover of darkness at the end of your street. It was the most extraordinary feeling to be able to disappear in one part of the city and emerge at an exact location a few hours later.
    They would stare in wonder at the fine Victorian brickwork and appreciate the sleek intersections with modern upgrades, documenting it with digital SLR cameras and video. But the book on the secret architecture of London’s sewers had been put on the back-burner after first Roddy, then Steve, had settled down and started families.
    Steve had called Roddy and shown him how the sewers were trending on social media that weekend. It was big news. They could have one last foray for old times’ sake, post fresh videos and rank big. What wasn’t to like?
    They’d entered the system near Herne Hill station late on Saturday afternoon, at the southern edge of the Victorian sewers laid out by Sir Joseph Bazalgette. Steve’s wife had insisted on seeing them off, asking them to check in every couple of hours. She’d even insisted on knowing a route plan, reminding him of his responsibilities towards his offspring. On the plus side, she’d acted as lookout as they disappeared down the manhole on the quiet suburban street. Good for his word, Steve had texted his wife after a couple of hours, and had to admit to himself that it added to the thrill knowing that someone outside the system knew where you were and what you were doing.
    Heading north, they’d soon come to the tributary coming down from Tulse Hill and Brockwell Park on their left, bringing completely fresh water into the system. They’d trudged downstream to the north for another hour, sensing the occasional vibration of an overground train. Now there was a different thunder. It was deeper and more encompassing than the passing of an overground train.
    “Victoria line, train pulling into Brixton,” said Roddy.
    “Gotta be,” said Steve. He sniffed the air and shone his flashlight around. “Smell the market?” They both sniffed the air. Under the stench of the sewage there was the unmistakable smell of Caribbean spices and rotting meat from the myriad food outlets in Brixton Village, and the halal butchers’ shops on Electric Avenue. Steve’s flashlight found a couple of fat rats feeding on some offal. The rats ignored them and continued to eat. Next to them was a child’s doll, its dirty clothes in tatters.
    “Monster rats!” said Roddy with a grin, stowing his flashlight and taking out his SLR.
    “Wasn’t there a Doctor Who story about giant rats in the