She had not a doubt that Darius had despatched him at once to Ecbatana to meet Phraortes, or at least to inquire into the state of affairs in the city.
She knew that no one could outride Zoroaster, and that there was nothing to be done but to await the issue.

It was not possible to send a word of warning to her agent--he must inevitably take his chance, and if his conduct attracted suspicion, he would, in all probability, be at once put to death.

She believed that, even in that event, she could easily clear herself; but she resolved, if possible, to warn him as soon as he reached Shushan, or even to induce the king to be absent from the palace for a few days at the time when Phraortes might be expected.

There was plenty of time--at least eleven days.
Meanwhile, a desperate struggle was beginning within her, and the letter her woman had brought her hastened the conclusion to which her thoughts were rapidly tending.
She felt keenly the fact that Zoroaster, who had been so cold to her advances in former days, had preferred before her a Hebrew woman, and was now actually so deeply in love with Nehushta, that he could not leave the palace for a few days without writing her a word of love--he, who had never loved any one! She fiercely hated this dark woman, who was preferred before her by the man she secretly loved, and whom the king had brutally declared to be the most beautiful woman in the world.

She longed for her destruction as she had never longed for anything in her life.