Mendel was speaking to the cleaning woman whom the monastery employed to keep the prelate's quarters free of dirt and dust. Her answer to his question had been a bit defensive; like everyone she was worried about events and felt that some of the blame might be coming her way.

"So you cleaned the guest room immediately after the officer left? Did you clean all the room? The fire grate, the hearth and the tiles, for example, did you clean those and thoroughly?"

"Lord bless you sor, of course I did. As I does every mornin'. There weren't a spot o' dirt left on those tiles when I had finished."

So Mendel had the answer to at least part of his question; the mud he had found had come from a boot and was left there later in the day, possibly by the arsonist himself. "Thank you," he said, "and who cleans the boots of our guests?"

Armed with that information he went to fine Tomaz, the son of one of the day laborers. There he got a similar answer. All the Abbot's guests usually left their boots outside their doors the night before. Tomaz collected them early, before dawn, blackened and buffed them, and had them back outside the doors before the first light.

"Except that day, sir," he said to the monk, "I remember that none of the officers left out their boots. They must have been working late, or just forgot, or sumthin' 'cos there were none when I checked. So I didn't clean none." He added with perfect logic.

So Mendel wandered away from the servant's quarters somewhat more knowledgeable, but none the wiser. He had one more visit to make.

"Come in Brother Gregory," Abbot Napp called out seeing, and hearing the monk knock at his door. It was a Saturday morning and he was expecting Msgnr. Schrattenbach to arrive at any moment to begin making the arrangements for the tribunal that would examine Brother Matthew. Any distraction was welcome. "How are your investigations going? Has Brother Matthew been able to explain himself?"

"Brother Matthew continues to proclaim his innocence, often in quite loud terms and always most vociferously," Brother Gregory said, coming into the room and helping himself to one of the Abbot's cigars. "Despite all the evidence against him, he maintains that he was never near your nephew's room and certainly has never been engaged in anti-military sabotage. On this he refuses to budge."

Abbot Napp shook his head. "Most foolish," he murmured sadly, "it would be better for him to confess and ask the Bishop for mercy before the examination. Who knows what the tribunal will find, and, I'm sorry to say, Brother Matthew has no friends among the examiners, so the outcome could be quite harsh. I've heard that the army is getting impatient with all the difficulties and delays it is encountering during this mobilization, and is looking for officers to blame. My nephew could be in trouble himself over this incident, and wants to be able to pass on some of that blame to the Hussites."

"But what if Brother Matthew is innocent?" Brother Gregory asked, not quite believing in the innocence of his friend himself.

"Unlikely," Napp shook his head. "But what have you come to see me about?"

"Were you one of the first people to enter the guest room after the fire had been detected and put out?" Brother Gregory asked.

"Yes," answered Napp, somewhat surprised at the question. "As far as I know, only the Sergeant-major had been in the room between the time the arsonist struck, and the fire was detected."

"Think carefully. Did any one of you go anywhere near the fireplace?"

Napp did think for a moment, then answered "Not at first, but after the broken Krautstrunk beaker was found, we all went over for a look."

"Did any of you actually step inside the hearth and onto the tiles?"

"Oh no, not that I can remember, we were all afraid of stepping on the broken glass. But why do you want to know this?" the Abbot could not help asking.

"I'm not sure," Brother Gregory told him, "but if what you say is right, then I think I have the first clue as to the identity of the saboteur. He left a small piece of himself behind, and all I've got to do is see if it has anything more to tell me."

Leaving a bewildered and confused Abbot behind, Mendel made his way back to his own rooms, and started to set up his newly repaired microscope.