The Shadow circled the end of the freight car and remained unseen.

The Shadow had a strange ability for remaining unseen, even when persons were looking at the very spot where he might chance to be.

Were, perhaps, striking from there, and thus remaining unseen.

It would not have taken them a minute, and they could have remained unseen.

That doesn't seem likely, since none of Capa's other work has remained unseen for so long.

The parents also would be watching, remaining equally unseen, but others had no reason to hide.

He leaves without taking a last look, believing that the key is remaining unseen.

There was no place where an unconscious person could have remained unseen.

You could have held a distinct advantage by remaining unseen.

Perhaps then would be the best time to attack, but only if he had their close trail by then and remained unseen.