She thought now, with all the concentration of her ingenuity.

One chance presented itself to her mind at once.

They most pass the pillar behind which was the concealed entrance to the Moorish gallery above the throne room, and it was not at all likely that Dona Ana should know of its existence, for she never came to that part of the palace, and if Inez lagged a little way behind, before they reached the spot, she could slip noiselessly behind the pillar and disappear.

She could always trust herself not to attract attention when she had to open and shut a door.
The Princess spoke rarely, making little remarks now and then that hardly required an answer, but to which Inez answered in monosyllables, speaking in a low voice through the thick veil she had drawn over her mantle under her hood, on pretence of fearing the cold.

She thought it a little safer to speak aloud in that way, lest her companion should wonder at her total silence.
She knew exactly where she was, for she touched each corner as she passed, and counted her steps between one well-known point and the next, and she allowed the Princess to gain a little as they neared the last turning before reaching the place where she meant to make the attempt.
She hoped in this way, by walking quite noiselessly, and then stopping suddenly just before she reached the pillar, to gain half a dozen paces, and the Princess would take three more before she stopped also.