* * *
The rat scurried purposefully down the disused rail track, its nose twitching as it scented the air ahead. It could smell something sweet, something nourishing, something it hadn’t smelled in a long time. It was joined by a second rat, a female several inches shorter. A third rat emerged from the darkness to their left, its eyes glinting and its ears forward.
The three rates began to run, their paws crunching on the gravel around the sleepers. Soon they were among more rats. A dozen. Twenty. All heading the same way. Before long the tunnel entrance was nothing more than a small squashed circle behind them. The three rats stopped running: there were too many furry bodies ahead of them to keep up the pace. They slowed to a walk, then they had to push their way through the mass of rodents to make any progress. The sweet smell was stronger, driving them into a frenzy. Food. The food was close by.