Martin Hewitt put the paper on the table and looked keenly in my face. "It is a trap," he said. "It is a trap to catch me—unless I flatter myself unduly."
I could not understand. "A trap?" I repeated. "But how?"
"Why should Mayes need to send his confederate instructions by written note? We know the nature of his hold over his subordinates, and we know that it means personal communication. Also, the cheque was in Mayes's own hands last night. More, Mayes knows very well that I have read that cypher—has known it for some time; otherwise how could we have discovered the bonds in the case of the Lever Key? Also, Mayes knows that we have his cheque-book and know his bank. Didn't I assure you we were watched last night? I believe he knows all we have done. In such circumstances he might risk his jackal's liberty by sending him on the desperate chance of cashing a cheque, but, knowing the risk, he would never have let him come with information on him. And least of all would he have let him come carrying a vital secret written in that very cypher which he knows I read many weeks ago. And then see how that message, instead of being concealed, was positively brought to your notice! That man Broady Sims is a cunning rascal, and the police know him of old as a skilful swindler and bill-forger. A man like that doesn't get rid of a compromising scrap of paper by trundling it out under your nose just at the moment he is arrested, when the attention of everybody is directed to him; no, he would wait his opportunity, and then he would probably slip it into his mouth and swallow it. As it is, he would seem to have succeeded in dropping this paper full in your sight, with an elaborate pretence of secrecy. Now this is what has been done, Brett. That man has been sent to cash a cheque, with very little hope of success, or none, because the first move that Mayes would anticipate on our part would be the watching for him and his cheques at the bank in Upper Holloway. If by any chance the cheques had been cashed, well and good, no harm would have been done, and then Mayes could have gone on to arrange for drawing the rest of his balance—could probably have quite safely come himself to draw it. But if on the other hand, as he fully anticipated, Sims was arrested, what then? Nothing was lost but a penny cheque-form, and even Sims—though Mayes would care nothing about that—could only be searched and then released, for the cheque was perfectly genuine, and there was no charge against him. But since he would certainly be searched, that cypher note was given him, with instructions to make a conspicuous show of attempting to get rid of it. Now that note was written in a cypher which Mayes knew was as plain as print—to whom? To me. I am on his trail, and this note is deliberately flung in my way, open as the day, but with every appearance of secrecy. I am his dangerous enemy, and he knows it—as he told you, in fact, yesterday. If he can clear me away, he can take breath and make himself safe. The purpose of this note is to induce me to go, alone, to this place on Channel Marsh to-night at twelve, in the hope of learning where to find Mayes. There I am to be got rid of—murdered in some way, for which preparation will be made. Mayes judges my character pretty well. He knows that, in such circumstances as he represents, Sims being kept away from his appointment, I should certainly go and take his place, and use his password, to learn what I could. And, Brett, that is precisely what I shall do!"
"What? You will go?" I exclaimed. "But you mustn't—the danger! We'd better both go together."
Hewitt smiled. "Why not forty of us?" he said. "No. Here is a chance of bagging our man, for, however I am to be arranged for—whether by shot, steel, or the tourniquet, I make no doubt it is Mayes himself who is to do it. You shall come, however, you and Plummer at least. But we will not go in a bunch—you shall follow me and watch, ready to help when needful. This Channel Marsh is an empty, dark space between two channels of the Lea. It is among the Hackney Marshes, lying between Stratford and Homerton, and I fancy there is a deserted house there, though I can't remember ever having seen it. Do you know it?"
"No; not in the least."
"Well, I must reconnoitre to-day, and that with a lot of care. I think I told you I was convinced of being watched, and that is a thing you can't prevent in a place like London, if it is skilfully done. Now, Brett, you have done very well this morning. If you want to be on the scene of action to-night at twelve, you must get leave from your editor, mustn't you? How's your wrist?"
It was still extremely stiff, and I told Hewitt that I doubted my ability to hold a pen for two or three days.
"Very well, then; get off and convey your excuses as soon as you please. I shall have a talk with Plummer, and then I shall take a few hours to myself, by myself, in somebody else's clothes. Be in your rooms all the evening, for you may expect a message."