She watched Allan turn and face the edge of the circle as though confronting some invisible menace.

Then the invisible menace dragged me through the doorway into the interior of the castle.

That left only The Shadow - a powerful, invisible menace.

Rhodan, I've fought against this invisible menace for 10 years.

The air shifts with an invisible menace, like radioactivity.

Flinching, Pedius put up his hands to ward off some invisible menace.

But either you will agree to trust me or one day the invisible menace will have gobbled up your whole empire.

The encounter with this invisible menace had shaken him to his core and left him weak.

Yet somewhere out there lurked this mysterious invisible menace.

Again, the invisible menace of the underworld had stepped in to intervene against men of crime.