"What's an alien?" Cain echoes thoughtfully. "They're the inhumanity amongst the stars. But in more practical and identifying terms, they're anything that isn't human. It's fairly obvious when something's a xeno, usually," he says with a laugh. "Far too many of them come with fangs and claws the size of your arm, if you ask me."

"But some don't look too different. Take the Eldar, as an example. If it wasn't for their ears, you could almost mistake them for human. It's more than unnerving, to be honest."