When Ridley Scott returned to the Alien franchise with Prometheus in 2012 hopes were high that the venerated director would give audiences the kind of scares associated with his original 1979 classic. What we got instead was a disjointed meditation on creation with a group of characters whose actions often seemed more alien than the series’ title creature.

During production of Alien: Covenant word of mouth suggested that Scott and the production team had taken onboard complaints that Prometheus had strayed too far from the formula and that this time… this time… we would see our beloved xenomorph restored to its full, chest-bursting glory.

Picking up ten years after we last saw Noomi Rapace and Michael Fassbender (as Dr Elizabeth Shaw and David) wander off into deep space to find mankind’s creators, we focus now on the crew of the colony ship, Covenant, heading for a remote planet, Origae-6, with two-thousand colonists and a thousand embryos on-board, monitored by an upgraded android resembling the earlier David, named Walter (also played by Fassbender).

Of course things go wrong on the mission and the ship is soon taking a detour to investigate a human signal coming from an alien planet – seemingly also ripe for colonisation.

Before you can say “In space, no one can hear you scream” the landing party runs into further trouble and for a while the film seems to be leading us along a familiar path with new forms of alien creatures, the neomorphs, making short work of everyone.

Then Fassbender’s David reappears and the film lurches into gothic Hammer horror territory. This might seem like an intriguing diversion but while Covenant IS more of a horror movie than Prometheus, Scott and his writers appear to have lost all interest in the alien. The real monster here is David, serving as Victor Frankenstein to the now dethroned star of the franchise.

Events reach a climax on the planet and the survivors return to the Covenant for a bizarre and utterly shoehorned in final fifteen minutes which attempts to recreate elements of both Scott’s 1979 original and James Cameron’s equally loved 1986 sequel, Aliens.

I have too much respect for Scott to suggest that Covenant’s Reader’s Digest abridged-version finale was a studio-dictated necessity but that is, sadly, exactly what it feels like. Events are rushed through and more crew members are dispatched with such rapidity that it would be easy to miss the true (and highly effective) horror enacted by David in the film’s final moments.

There are two movies struggling against each other, the attempted return to the scary roots of the franchise and the story Scott and co. are really interested in, that of David and Walter and the struggle with what they are, where they come from and their quest to find answers among the stars – which provide some of the most interesting moments of Covenant. Sadly, these two movies fail to cohere and we’re left with a story that satisfies neither requirement.

Scott is far too good a director for Covenant to be a disaster: there’s lots to enjoy and admire and there are moments of beauty, of intrigue and of genuine horror (and also, sadly, of unintentional humour… the baby alien raising its arms to copy David is a series low point). Unfortunately the ambition to turn the franchise into something of wider philosophical concerns dilutes the simple funhouse horror of the central creature, leaving him somewhat toothless and the film itself oddly schizophrenic.