It seemed as though he had been in the odd, alien world for months.

This was an alien world, could they ever make it home?

Data knew that on any alien world there was a chance of a problem.

It was an alien world out of which they now had to fight.

Ben was looking at me as if he'd suddenly found himself in an alien world.

You have been taken to a strange and alien world.

Or thought about how an alien world could be different.

This was an alien world, light years away from his home.

They live in an alien world where we couldn't survive.

We have been fighting a war too, against this alien world.