The Inimical Prey

Summary: The Doctor goes to investigate a distress signal from a stranded space crew, but gets more than he bargained for when he discovers the planet they've crashed on is infested with xenomorphs and a hunter species that views humans as fair game.

Set just after The Runaway Bride.

Disclaimer: I don't own the characters, aliens etc. They belong to Ridley Scott, James Cameron, Russell T. Davis, and whoever else is involved in creating the many elements this crossover is composed of.

A/N 26/7/11: I've started rewriting parts of this, as I'm aiming to make it longer and better. Anybody re-reading this may have noticed a few changes in it already, and I hope you think it's been an improvement!

Chapter One – A Call For Help

As usual, he didn't really know where he was going. He normally made decisions as to what his next destination might be on the spur of the moment, or he let the Tardis decide for him, but just this once he didn't really feel like going anywhere. He was happy to just drift along rather aimlessly through the Orion Nebula until finally something came along to spur him into action.

Truth was, he didn't have much enthusiasm for doing anything at the moment. He still couldn't forget about Rose. All that business with the Racnoss had been a distraction, but it hadn't lasted. He couldn't get her face out of his head, the way she'd looked the last time he saw her. The final time he would ever see her. As much as he missed her, it wasn't just the sense of loss that was eating away at him: it was a feeling of anger too, directed at himself for choosing the wrong time to hesitate. He'd had one chance to say it to her, and he'd blown it. And that was something he'd never forgive himself for.

What he needed was to get away from Earth for a while. The memories of her were still too raw for him to want to stay there much longer. He'd return there eventually, of course: he always did. He knew from experience it wouldn't hurt this bad forever, and it probably wouldn't be all that long before he found himself itching to be back in 21st century London. But right now he just needed to get away.

He hadn't been specific in his destination, but just set the Tardis on a generic course into the future a few degrees east of Betelgeuse. And now here he was, waiting for something to happen even though there didn't seem to be any signs of spacecraft or inhabited planets for lightyears around. He was beginning to think about where he could go and that it would help take his mind off things if he could just make a definite decision, but then something started blinking on one of the screens of the Tardis' console and a beeping noise began to sound.

"Alright, what have you found?" the Doctor said aloud, partly to the Tardis and partly just to break the silence. He didn't like it being this quiet; he always liked to have someone around to explain things to, but he was on his own now.

Intrigued, he quickly found the relevant screen and rotated it on its stand to get a better look at it. The screen was reporting the receipt of a transmission, but that didn't entirely make sense. The Tardis was ten lightyears into the nebula, which was made up almost entirely of rock, hydrogen and dust: there was nowhere for the transmission to be coming from. Unless, the Doctor thought, I'm picking up an echo, or an old signal of some sort. Flicking a few more switches and pressing a few buttons on the console, a stellar co-ordinate map appeared on the screen and a cross-hair began to trace the signal's location to its source star system. A six digit number began to count up and down rapidly in the top left hand corner of the screen as the Tardis' systems pinpointed the date.

After a few seconds, a big red box appeared in the middle of the display and a beep sounded as it reported the message: Mayday Signal Detected, Location: Messier 42 IO3658, Earth Date 2261 AD.

"A mayday signal," the Doctor said to himself as he read off the screen, "I think I like mayday signals. They may mean things might be about to get dangerous, but at least you can always rely on them to be interesting." Impulsively, he'd already decided he was going to follow it. Something like this was exactly what he needed to distract him. More importantly, it was a distress call, meaning somebody out there needed his help.

He flicked a few more switches and then placed his hand on one of the levers on the Tardis' console. "Right, let's see where you're coming from," he said as he pulled the lever down. "Allons-y!" The familiar whooshing noise began to sound as the pump was activated in the central column and the Tardis shifted direction.

Had the Doctor taken time to interpret the rest of the transmission, he might have thought twice about following it blindly to its source.