10 Best Movies With An Unseen Enemy

4. The Terminator

In fairness, all of the Terminator movies feature explicit robotic antagonists chasing down our flesh-and-blood heroes, but it's important not to ignore the fact that the series' real antagonist is actually operating invisibly from behind the curtain.

The T-800 (Arnold Schwarzenegger) may play the corporeal baddie of the original Terminator, but it's quickly established that the murderous cyborg was sent back in time by Skynet.

Skynet is of course the self-aware A.I. construct which is plotting to kill Sarah Connor (Linda Hamilton), preventing an uprising against the machines and ensuring humankind is swiftly annihilated with a few handy nukes.

There's always been an abject, fascinating creepiness to Skynet, this formless intelligence which has learned at a geometric rate far beyond human expectation or control.

Sadly, the last two Terminator movies made the misguided decision to give Skynet personified humanoid forms - Dr. Serena Kogan (Helena Bonham Carter) in Terminator Salvation and the T-5000 Terminator (Matt Smith) in Terminator Genisys.

But with the upcoming Terminator: Dark Fate de-canonising both movies, it's safe to say that Skynet is once again an unseen yet terrifyingly calculating antagonist.