For only a moment, Sarafina felt an alien presence in her mind.

A hostile alien presence has descended upon the Earth's waters.

He said that they could read each other's thoughts and found it relatively simple to sense an alien presence.

And, perhaps, an intelligence that only now was beginning to react to his alien presence?

In the center of the chamber was a scintillating alien presence.

"We have reason to believe that you are harbouring an alien presence."

Price hadn't even known there was an alien presence in the Rookery.

Yes, he'd gone to Starlab looking for traces of alien presence.

He manages to make the alien presence go away for nearly seven years.

His face was distorted with terror and something else, some kind of alien presence.