Garth Ennis has called Alien one of his favourite films. Its 2012 prequel, Prometheus, avoided the story choices he'd been imagining... so he turned his own idea into this comic. You might be wondering why he didn't approach Dark Horse (or these days Marvel) and write one of their many, many official Aliens stories, but maybe that question answers itself.

This isn't an Alien story, though. It's dedicated to H.R. Giger and it's easy to imagine how it could be adapted to fit into that franchise, but it's original. For starters, its not-an-Alien is even more gross, although just as dangerous and scary. Ennis has also cited Event Horizon, Pitch Black and Pandorum as influences when writing this. It's portraying a similarly dirty future, in which a heavily industrialised Earth resembles a "tumour breathing through a smokestack" and the bored, bad-tempered crew of spaceships are liable to commit suicide.

Mankind doesn't think intelligent alien life exists. We've never found any. One day, though, the Caliban has a gruesome hyperspace accident. We're shown exactly how disgusting that might be, but worst of all is the thing that might have been alive on the alien ship they crashed with.

This one's unusually positive for a Garth Ennis horror story. Its ending won't make you open your wrists. (Crossed, Ribbon Queen and A Walk Through Hell leave you no hope at all.) The good guys triumph, although the being's probably still out there. I can easily imagine this storyline being turned into a hypothetical film that would be decent but nothing special and would probably fare okay at the box office. (You might need to flesh it out a bit, though. There's not enough here to carry a two-hour movie.) It's conventional. It wouldn't violate anyone's ideas of what a horror flick should be. This makes it less interesting than those three other Ennis horror titles I cited, but easier to recommend to normal readers.

I quite enjoyed it. It has memorable SF/horror imagery, some reasonably likeable heroes and lively dialogue. The latter's an Ennis speciality and it shouldn't surprise anyone that he excels at bringing SF down to earth. This is also one of Ennis's few SF works, bar of course his 2000 AD period and the occasional licensed property like Star Wars and Dan Dare. It's not one of his standout books, but it's worth a read.