The widow had taken the envelope, of course. She must have snatched it up during the few seconds he had turned his back on her in order to step across the hall and retrieve her bag, and have replaced it at the same instant with this empty one which she had no doubt taken from his own writing-table while he stooped beside her to pick up her glove.
Gimblet fetched one of his own blue envelopes and compared it with the substitute. Yes, they were alike in every particular. The watermarks were the same and showed that she had used what she found ready to her hand.
It seemed, then, that the coup was not premeditated. But why, why, had he let her escape so easily? If only he had been a little quicker about following her, and had not wasted time looking for Higgs! She had had time to get clear away; and he, bungler that he was, had thought it of little consequence, and had afterwards stood poring over a catalogue in the hall, having decided that her morals were no business of his. Ass that he had been!
Who was she? Probably some one known to Lord Ashiel, or why should she have wanted his letter? Well, Ashiel must have met her on his way out, and would in that case at least be able to provide the information as to who she was. Still, more people might know Ashiel than Ashiel knew, and it was possible that that hope might fail. No doubt she was a member of the society the peer had so rashly entangled himself with in the days of his youth; one of those enemies of whom he had spoken with such grave apprehension. Had she followed him into the house and forced her way in on a trumped-up pretext, on the chance of hearing or finding something that might be useful to her Nihilist friends, or had she known that Lord Ashiel intended to leave some document in Gimblet's keeping, and come with the idea, already formed, of stealing it? Such a plan seemed to partake too much of the nature of a forlorn hope to be likely, but whether or no she had expected to find that letter, Gimblet could hardly help admiring the rapidity with which she had possessed herself of it without wasting an unnecessary moment.
She must have been safe in the street and away with it, in less than five minutes from when she first saw it. Oh, she had been quick and dexterous! And he? He had been a gull, and false to his trust, and altogether contemptible. What should he say to Lord Ashiel? Why in the world hadn't he locked up the letter when Higgs brought it in? This was what came of making red-tape regulations about not being disturbed. After all, he comforted himself, she would be a good deal disappointed when she found what she had got. The key to a cipher; that was all. And a key with nothing to unlock was an unsatisfactory kind of loot to risk prison for. Evidently she expected something more important; perhaps the very documents she had invited Gimblet to steal for her, regardless of expense. This, he thought, was a reassuring sign for Lord Ashiel. For it was plain they meant to steal the papers, if they could; but not so plain that they looked to murder as the means by which to gain that end, since they applied for help from him.