The alien structure was the core of a vast magnetic field.

"Do you think these people might be able to shed some light on that alien structure we ran into out there?"

And the cathedral-like alien structure that had clearly caused the miracle.

They now knew a great deal about the way the alien structure was configured.

It looked so ordinary on the outside, but it was an alien structure.

He glanced at the screen again, reminded that half their party was in the alien structure.

In the near darkness, the huge alien structure was definitely glowing, although slightly.

He often likened complex alien structures to some familiar animal or another.

American scientists discover human remains inside one of the alien structures.

He knew these figures had not been carved by men; they were part of the alien structure.