Introduction
They came when no-one was expecting them, and by the time anyone had realised that what they were dealing with was more than your usual serial killer they had already left thirty people dead behind them. The remains caused confusion, more so when one of them was identified from her clothing as being an eighteen year old college student who had been talking to friends only a day before. From what they had been able to determine from the dessicated remains, the CSI team had thought they were seeking some poor old lady who had been dead for months.
Everything changed then, and suddenly it wasn't a matter for the police any more, but for the army. They came determined to hunt the killers down and, to their credit, did not flee when confronted with aliens who seemed able to suck the very life out of people with their hands. They came in numbers, for the aliens numbered only a half-dozen, and perhaps enough guns would be able to defeat that terrifying power.
They were not defeated. Instead, they retreated, returning to their ship. The reaction when it started to rise was fast - shoot it down, get rid of it, kill the threat while there was still a chance - but not fast enough. Monitoring systems said that the radio call had already gone out, perhaps far enough and quickly enough to reach the creature's homeworld or ship, however many lightyears away it might be. The leaders of Earth looked at each other and knew that now, if any, was the time to co-operate while there was still time, before the main fleet followed this scout-ship to the new planet they had found.
They called them the Wraith, ghosts that walked and brought death on their hands, and no country objected when their brightest and best children were demanded in order to prepare to fight it. As they were quick to point out, without those children, there might be no children at all left to fight for.