The profit-driven nature of filmmaking usually means that, if a movies a hit, sequels follow.

Shot mostly in Rome on a low budget,Beyond The Doorturned a handsome profit of around $15m.

Another unrelated sequel,Beyond The Door IIIfollowed in 1989, and was about a demon-possessed train.

This time, killer mutant piranhas terrorise unwary locals in the Caribbean.

And just to make things more interesting, the piranhas have been given the inability to fly.

And thus, one of the more curious sequels in movie history was born.

Jamie Lee Curtis also turns in an easy-to-miss cameo as the voice of a telephone operator.

What this ones about:The Howlingtook a trip down under with this largely unrelated sequel.

My Daliesque description of marsupial human women with pouches generated expressions of shock, Mora later wrote.

As the infection spreads, the poor soul then begins to give birth to lots of baby snakes.

As bizarre as it sounds,Curse IIbenefits from some creatively horrible special effects from Screaming Mad George.

What this ones about:House IIIdrifted yet further from the originals premise.

Tenuous link to the previous films:None at all.

With a creative genesis like that, how could the movie fail?

Needless to say, studio executives had other ideas.

What this ones about:Four years after the original, this unrelated sequel appeared with the subtitleNighty Nightmare.

Most tenuous link to the previous films:Aside from the obvious genre trappings, not a lot.

Some of its special effects scenes really push the boundaries of taste.

Pierce Brosnans nowhere to be seen, and Jeff Faheys character is now played byMax Headroomactor Matt Frewer.

The teenagers didnt turn up to seeBeyond Cyberspace,and the third movie never happened.

It was supposed to be a different project, and it was re-edited.

The result, she maintained, was bad.

A second sequel was threatened a few years ago, but so far, nothings come to light.

Instead, its about Nathan Fillions grieving Abe, whose family was killed by a maniacal gunman.

Tenuous link to the previous films:None.

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