The caller had been smart enough to escape observation, on each occasion.
Only by keeping close against the surface could The Shadow be sure of escaping possible observation.
He seemed to be trying to escape observation from the rest of the guests in the crowded ballroom.
Of course, the result was that the pair took risks which did not escape observation.
He glanced about again, and was glad to have, apparently, escaped observation.
There, I may be able to watch him and still escape observation.
"For it must be well hidden to have escaped observation so long," Tom decided.
The great thing was that he had escaped observation.
He looked up from the final course plotting that would escape both the satellite and orbital observation.
The way he had taken them was hidden from view, and there was a chance they'd escaped observation.