诺伍德的建筑师（24）（在线收听）

“There's the advantage of being a builder,” said Holmes, as we came out. “He was able to fix up his own little hiding-place without any confederate—save, of course, that precious housekeeper of his, whom I should lose no time in adding to your bag, Lestrade.”

“I'll take your advice. But how did you know of this place, Mr. Holmes?”

“I made up my mind that the fellow was in hiding in the house. When I paced one corridor and found it six feet shorter than the corresponding one below, it was pretty clear where he was. I thought he had not the nerve to lie quiet before an alarm of fire. We could, of course, have gone in and taken him, but it amused me to make him reveal himself; besides, I owed you a little mystification, Lestrade, for your chaff in the morning.”

“Well, sir, you certainly got equal with me on that. But how in the world did you know that he was in the house at all?”

“The thumb-mark, Lestrade. You said it was final; and so it was, in a very different sense. I knew it had not been there the day before. I pay a good deal of attention to matters of detail, as you may have observed, and I had examined the hall and was sure that the wall was clear. Therefore, it had been put on during the night.”

“But how?”

“Very simply. When those packets were sealed up, Jonas Oldacre got McFarlane to secure one of the seals by putting his thumb upon the soft wax. It would be done so quickly and so naturally that I dare say the young man himself has no recollection of it. Very likely it just so happened, and Oldacre had himself no notion of the use he would put it to. Brooding over the case in that den of his, it suddenly struck him what absolutely damning evidence he could make against McFarlane by using that thumb-mark. It was the simplest thing in the world for him to take a wax impression from the seal, to moisten it in as much blood as he could get from a pin-prick, and to put the mark upon the wall during the night, either with his own hand or with that of his housekeeper. If you examine among those documents which he took with him into his retreat I will lay you a wager that you find the seal with the thumb-mark upon it.”

在我们往外走的时候，福尔摩斯说：“这是建筑师的有利条件。他能给自己准备一间密室而不需要任何帮手——当然，他那个女管家除外。我应该马上把她也放进你的猎囊。”

“我接受你的意见。可是你怎么知道这个地方，福尔摩斯先生？”

“我先断定他就藏在屋里。当我第一次走过这条走廊的时候，发现它比楼下那条同样的走廊短了六英尺，这一来他藏的地方就十分清楚了。我也料到他没有勇气能在火警面前呆着不动。当然，我们也可以进去把他抓住，但是我觉得一逼一他出来更有趣。再说，雷斯垂德，上午你戏一弄了我，也该我来迷惑你一下作为回敬了。”

“嗯，先生，你的确向我报复了。但是你究竟是怎么知道他藏在屋里的呢？”

“那个拇指印，雷斯垂德。你当时说它是决定一性一的。在完全不同的意义上，它真是决定一性一的。我知道前天那里并没有这个指印。我对细节非常注意，这一点你也许知道；而且那天我检查过大厅，墙上确实什么也没有。因此，指印是后来在夜里按上去的。”

“但是怎么按上去的呢？”

“很简单。那天晚上他们把分成小包的字据用火漆封口的时候，约纳斯·奥德克叫麦克法兰用大拇指在其中的一个封套一上的热火漆上按一下使它粘牢。这个年轻人很快而且很自然地这样做了，我相信连他自己也忘了这件事。很可能这是碰巧发生的事，奥德克本人当时并没有想要利用它。后来他在密室里盘算这件案子的时候，忽然想到他可以利用这个指印制造一个可以证明麦克法兰有罪的确证。他只要从那个火漆印上取蚌蜡模，用针刺出足够的血涂在模子上面，然后夜里亲自或者叫女管家把印按在墙上就行了。这是天下最简单的事情。如把他带进密室的那些文件检查一遍，你准能找到那个有指纹的火漆印，这我可以打赌。”