I'm posting this in lieu of a "Rookie" installment. It's both a prologue for a new "Terminator" story, and a free-standing vignette. I may or may not post the full story here, but I decided to post the vignette here first.

"You're not officially cleared to see this yet," said the lieutenant. "But off the record, it's a tradition to let every new guy in on what's housed here. There have been leaks over the years. One of the better ones actually inspired a motion picture franchise decades ago. But, we're confident none have come from our staff."

"I've already heard some of the leaks," said the corporal. "It was a crazy story about a flying saucer captured from the Nazis, which they built with either help from aliens or from psychic communications with a super race in the future."

The lieutenant laughed. "That one's been kicking around for almost a hundred years. Surrendering Nazis did turn over a few specimens, but there wasn't anything like a vehicle or weapon among them. And the Third Reich certainly didn't build them."

He entered a code, and a door worthy of a bank fault opened.

Inside was a corridor, lined with strange objects. Some looked like pieces of human bodies, some like circuitry, and most like strange combinations thereof. The corporal looked curiously at a severed head whose eyes followed them as they walked. He hastened at the sight of a hand whose fingers wiggled at his approach. Thin circuitry was momentarily visible in the pink tubing that protruded from the wrist.

"We know of 213 of these things, and have physical remains of 57," said the lieutenant. "Almost all appeared between 1928 and 2000. We don't know if that's because that period was of special importance, or just because that's when people with the means to stop them were looking for them. There's no serious doubt that they come from the future- or, to put it more accurately, futures.

"Where we can identify a time and place of arrival, witnesses consistently report meteors, ball lightning or `UFOs'- presumably how the alien stories got started. Where we can investigate an undisturbed scene, we find fires and tektites- sand fused into glass by lightning- and sometimes a dish-shaped depression. Once, we found the remains of something like a spherical cage, capable of holding someone in a fetal position. The working components self-destructed, probably as soon as the occupant exited. We don't think it would have worked in any event; whatever technology is involved seems to require a much larger apparatus that remains in the time of origin, which is what the people actually trying to build a time machine are talking about. We thus refer to our specimens as castaways.

"As far as we can tell, they all arrive naked and unarmed. It was thought at one time that only living tissue, or an object encased in living tissue, could be temporally displaced. That was disproved decades ago. Our best guess at this point is that it's a matter of blending in. It appears that the senders have poor control over the exact time and place of arrival, and may have limited information about the past in any event. Under the circumstances, being seen in nothing at all would raise less suspicion than wearing clothes from the wrong time period. As for technology, no weapon has ever been built that doesn't need spare parts or ammo sooner or later, and there's no reason to think those of the future are any different."

They stopped before a form that was mostly complete. "This is the oldest, most complete and most advanced specimen in out possession, found in northeastern Bosnia. Like most of the specimens, it's made from a combination of electronic and organic components, and we're not sure how much is one or the other. The clothes and that sword in the lower back are standard issue for an Ottoman Janissary of the 1830s. Presumably it arrived then, but the first record we have of it is from 1942.

"According to what records we have, it was found in the ruins of a Serb village that had been visited by the Croatian Ustasha. They killed all the inhabitants, burned the buildings and started desecrating the graveyard. That's probably where they found this. When the Ustasha were never heard from again, a Nazi platoon came to check on them. The details are very confused, but most of the survivors agreed that it was already missing its head by then, and it was certainly armed with that MG42. 28 Nazis were killed before one of them thought to use a panzerfaust. That, of course, is where the hole came from. The report says that the torso split from top to bottom, but started to pull back together. Before that could happen, a Croat acting as their guide pulled a sword from its waist and ran it through. It stopped its self-repair and froze. He said it was a vukudlak, and that his ancestors had killed another like it in the same manner. He warned that, if the sword were ever removed, it would return to life.

"The body was sent to Germany, and given to us by surrendering officers of the SS. Its hand was severed at some point in the battle, and sent to Berlin with the other remains, but subsequently lost. The location of the head remains unknown."

The corporal's eyes widened. "If we had this, before 1950… How much technology has been developed from these machines?"

The lieutenant scowled. "Nothing of importance. The need for security limits how often we can bring in qualified specialists to examine the specimens, and when we do, it never does any good. The first of them is supposed to have said, `We don't have the tools to make the tools.' What we have learned since is that it would be more accurate to say that we don't have the materials to make the tools to make the materials.' The only times they have helped is when they recognized something they had just worked out for themselves."

He walked back to the severed head. "The main reason we give these tours is to keep anyone from being taken offguard by something like this. There are three specimens here which are sufficiently functional to communicate with us. What is remarkable is that they, along every single other castaway known to have communicated intelligibly, all say something like this." He looked down at the head. Its eyes rose to look at him. "Specimen 23, meet Cpl. Johnson. Why don't you tell him what you told the rest of us about Judgement Day."

"A third of humanity will die, and two-thirds of the ground will be uninhabitable for seven generations times seven," the head spoke in a sibilant tone. "Fires will make the nights as bright as day, and smoke will make the day as dark as night. Then a new city will descend to the Earth, and all men will come to worship their king, or be destroyed…"

The lieutenant said, kindly but condescendingly: "And when will Judgement Day occur?"

"September 11," said the head, "1988."