The news that director Neill Blomkamp is moving ahead with his plan for a new Alien movie presents many more questions than it does answers. The saga that launched in 1979 with Alien, Ridley Scott’s claustrophobic space-slasher flick, and was revived in 2012 with the veteran British film-maker’s befuddled Prometheus, is a prime example of a franchise filming itself into a corner. And Blomkamp won’t be able to use time travel to get himself out the mess, as was done in two of Alien’s science-fiction peers, Terminator and Star Trek. So how should he do it? Or how shouldn’t he? Here are five things we don’t want to see in Alien 5.

1. Predators and space jockeys

The Alien series was never meant to be the sci-fi equivalent of Celebrity Deathmatch. Much-loved though the mandible-sporting alien mega-hunters of Predator may be, the thought of them turning up in the same universe as the xenomorphs – as they did in two ill-fated mid-naughties movies – is only slightly less upsetting than the idea of Spock wielding a lightsaber.

Ditto the space jockeys that were revealed in Prometheus to be god-like humanoids who spawned life on Earth but decided they didn’t like what they had created. These are best left for Ridley Scott’s planned sequel, which will supposedly explore their homeworld. (Good luck with that).

Director Neill Blomkamp on the set of his 2013 film Elysium. Photograph: Sportsphoto/Allstar/Columbia Pictures

2. Anything that happened in Alien 3

It’s not fair to blame David Fincher for killing off all the surviving cast of Aliens, including Ripley herself, by the end of his 1992 directorial debut. First of all, it sounds as if 2oth Century Fox in the early 90s was a terrifying place to work for a fledgling film-maker. The screenplay went through multiple rewrites and the project through several directors. Second, Weaver is said to have stipulated that the third film should excise the previous instalment’s blam-blam-thank-you-ma’am aesthetic in favour of a less gun-heavy approach – and include the demise of Ripley. It’s shows one should be careful what you wish for.

Despite the best efforts of legendary character actors, Alien 3 ended up being damp squib. The balls-to-the-wall blockbuster world developed by James Cameron on the previous film was suddenly invaded by multiple offbeat denizens of British kitchen-sink drama. It lacks even the exploitation-tinged nastiness of Alien: Resurrection, and the main event of note is shaven-headed Ripley’s final leap into the industrial furnace, Alien queen safely on board. After the emotional investment filmgoers had made in Newt and Hicks, the two are killed off before they even land on Fiorina 161, while android Bishop gets only a (beautifully-realised) cameo.

Ripley’s leap … Alien 3 – video

Blomkamp’s concept art for the new film features both Ripley and Hicks, the latter scarred from his encounters with the xenomorphs in Aliens, suggesting an approach that could involve simply forgetting that Fincher’s film ever existed. And who could blame him for that?

3. Human xenomorph Ripley

If you can’t use time travel or alternate timelines to bring back a much-loved character, you can always try cloning. Inexplicably emerging from the director of Delicatessen and Amélie (Jean-Pierre Jeunet), not to mention the future writer of Serenity and The Avengers (Joss Whedon), Alien: Resurrection (1997) gave us a Ripley brought back from the dead via sinister technologies. It’s a scenario that might just have been acceptable in the pages of 2000 AD but always failed to pass the logic test on the big screen. Clones do not maintain the personality traits of their “parent” donors, damn it!

While Weaver’s brutal performance as a creature with human and xenomorph lineage arguably took the character into intriguing new territory, the absence of the original Ripley meant the connection to all those fabulous moments from Alien and Aliens was slight.

4. Earth

Alien: Resurrection left the crew of the Betty poised above Earth. Where could the saga go from here? Might the next instalment reveal an alien stowed away on board (again!), unleashing the horrifying xenomorphs on Earth when the ship lands?

Please, no. The idea of an army of xenomorphs facing off against hundreds of thousands of badass human marines in a Lord of the Rings-style mass battle is anathema to the saga’s DNA. And as the makers of zombie apocalypse blockbuster World War Z recently discovered, the more you expand the scope of the narrative, the more you lose the human connection to those leading it. Ripley needs to be trapped in an alien horror show on some distant exo-solar hellhole, not leading the charge against rampaging xenomorph battalions like a sci-fi Boadicea.

5. Hamfisted explanations for Weaver’s age

If Blomkamp does return the story to the point just before Alien 3 jumped the xenomorph, how will the South African film-maker explain the fact that Ripley and Hicks are now almost three decades older than they were when we last saw them? Was there a malfunction in the cryotubes? Did the dropship make it back to Earth, with the new film kicking off 30 years later? What happened to Newt? And why would Ripley be called into duty again?

An Alien movie without Weaver – which Blomkamp initially had in mind – might make a lot more sense. But the geek world – and I have to say I, grudgingly and with trepidation – clearly believes he can make the first great Alien movie in 30 years.

If not, there’s always the option of taking off and nuking the whole project from orbit. It’s the only way to be sure we never get another terrible Alien movie.