She lowered her head, and fortunately her thin veil in the half-light did the rest.

She passed unnoticed and reached the door of the apartment.
As she opened it she heard the men turn and mount the stairs.
Instinctively she realized that something was wrong.

One of the men was her old enemy, Drummond, the detective.
They had not recognized her, and as she stood for a moment with her hand on the knob, she tried to reason it out.

Then she crept back, and climbed the stairs noiselessly.

Voices inside the apartment told her that she had not been mistaken.