Maybe not that long, he told himself.  Their technology can't be that different from ours.  The laws of science will work the same for them, won’t they?

He glanced down at the scanner as the tiny shuttle nosed its way through the debris cloud.  Automated systems were already picking up samples of alien metal, although the first sweeps suggested that alien hullmetal wasn't anything uncommon.  The researchers might speculate endlessly on new elements or previously undiscovered composites, but that was rather less than likely.  Or so Charles assumed.  If they started believing that there was something about alien technology that would be forever beyond humanity’s reach, they would always accept their own inferiority.

There was a ping from the console.  “Picking up traces of biological matter,” Henderson said.  “Sir?”

“Get it swept up by the drones,” Charles ordered, forcing down the surge of excitement he felt.  Despite himself, he desperately wanted to know what the aliens looked like – and what they called themselves.  Humanity had no name for them.  But while he had seen bodies survive seemingly devastating explosions, he didn't want to raise false hopes.  They might have found nothing more than blood and ashes.  “Then send them into quarantine.”

“Yes, sir,” Henderson said.  He looked up, suddenly.  “Will they catch colds and die?”

Charles shrugged.  The human race had discovered thirty Earth-like worlds – and seventy worlds that could be terraformed, although it was such a colossal investment that few were prepared to make the effort – but none of them had possessed a viral life form that was actually dangerous to humanity.  As far as anyone knew, Earth was the only world that had produced an intelligent race ... well, as far as anyone had known.  Unless the aliens were actually humans from a prehistoric space-based civilisation – and that seemed absurd – it was clear that there was more than one world that had given birth to an intelligent race.

“I doubt it,” he said, finally.  “Chances are that their biology will be so different from ours that our diseases will do little to them – and vice versa.”

Unless someone deliberately engineers a killing disease, he thought, grimly.  The Royal Marines had been involved in the suppression of genetically-engineered diseases – there had been several attempts to commit genocide using tailored viruses – and, despite all the international treaties, the world had come alarmingly close to disaster more than once.  Maybe we will take the gloves off when the aliens push us to the wall.

He looked down at Henderson, realising – not for the first time – just how young the Corporal actually was.  Charles had fifteen years in the Royal Marines, Henderson was barely out of training.  He’d never seen any real action, not down on the ground.  And Royal Marines rarely won plaudits for serving on starships that went into combat.  They were tasked to serve as groundpounders or space troopers, not starship officers.