Agent Apocalypse is called on to close the door on a small underground town.
Some leeches can grow to any size, limited only by the resources available.
One day a cave explorer stumbled across a large previously unexplored underground network of caverns. The caverns were found in central south-western Ontario, a large chunk of land right in the middle of the largest group of fresh-water lakes in the world. The AET got called in not just because of the caver’s claim of seeing a snake dozens of meters in length, but because of the fact that there were snake tracks to back up the claim. The cave network was also previously unexplored and so considered potentially dangerous to anyone who happened to find it.
What were initially thought to be snakes turned out to be fresh-water electric leeches. The AET called for army re-enforcements to explore the cavern network after sighting one of the electric leeches. The electric leech was enormous - two kilometers long. It turned out there was just a single entrance into the cavern network containing the leeches. The army quickly built a reinforced wall several meters thick with a nuclear blast door for an entrance into the cavern network. At the time it could not be explained why the army needed a nuclear blast door, and was kept secret. Allies suspected the construction of a nuclear bunker, but that wasn’t the case.
Further inside the cavern network a huge peculiar roughly-made fence network was found. A lot of bets were placed on who constructed the fence and what it was for. Junior AET personnel were queried for their opinions on the construct before they were told it was simply a fence. The typical response was that it was refinery network of some sort. Few personnel guessed that it was a fence, because of the sheer size of the fencing. The fence was an arrangement of oddly shaped metallic tubing with enough space between the tubes for a man to squeeze through. The fence extended around inner caverns blocking off all the entrances that were much larger than man-sized.
Senior AET staff deduced that the construct was in fact a simple fence designed to keep juvenile leeches within the cavern system, and to restrict them from leaving the cavern network. The electric leeches were determined to have at least as much intelligence as a beaver, potentially the leeches could be quite intelligent given their enormous size. It had been the leeches that constructed the fence network.
One day the really worrisome aspect of the discovery was made. In the centre of the cavern network was a much larger cavern. And it was somewhat like a snake pit. There were countless numbers of electric leeches all grouped together in the cavern. Based on the estimated size of the cavern, there were six million leeches present. Fortunately all the leeches were sleeping. Apparently they spend most of their time asleep.
A small town of army scientists sprung up overnight, just inside the cavern entrance, between the nuclear blast door and the leech’s fence. The town was approximately five miles away from leech city, and grew to be about 5,000 personnel. Special personnel (agent Apocalypse) was assigned to the blast door. If a leech approached within two miles of the underground town, the blast door was to be shut until it was determined safe to reopen it. There were strict noise regulations placed on the town. The idea was not to wake up any of the leeches.
Unfortunately, one day one of the adult leeches awoke and started moving towards science town. The town was under evacuation when finally the blast door was closed due to the proximity of the leech. 2,000 out of 5,000 army personnel were trapped underground in science town for approximately two years before the blast door was re-opened. Fortunately there were no incidences involving the leeches; personnel were simply trapped.