“Well, then,” said Tom, “let’s cast back and take another look at the topography, just where the shutter fell.”

Back we went over the ground once more, and stopped to examine cautiously the window with its green blind.

“That’s a fourth story corner room,” said Tom reflectively, “and the house next to it is only three stories. Why, you blind man,” he went on suddenly, “only one side of the shutter fell, so the attack couldn’t have come from the front. It must have come from the back of the house. Let’s go round and see what is just behind this.”

Round the square we circumnavigated, landing finally at a building some five stories high, whose first story showed the shelves and cluttered window of a second-hand book shop. Beside the shop a flight of stairs led to the upper stories. No sign gave evidence of any business carried on above the first.

“Here goes for the book shop,” said Tom, and we marched in.

A tall, stooping youth of exaggerated height, with lank and flaming red moustache, came wearily forward, stifling a cavernous yawn as he came. We repeated our stock inquiry to him. We were Colonials from Australia seeking our Cousin George, who worked in a laboratory. Did our friend with the red moustache know of any laboratory near? A gleam of interest lighted the slightly watery eyes.

“H’I don’t rightly know w’ether h’it’s h’a laboritory h’or not,” he began, “but there’s some sort h’of a bloomin’ show h’occupies h’our ’ole fifth. H’I’ve never been h’ible to see h’inside h’it yet. You might try h’a shot h’at h’it ’owever.”

We received the volley of misplaced aspirates with joyous hearts, noting the gleam of avid curiosity in the watery eyes, as the clerk thought of the mysterious laboratory on the top floor. All he could tell was that the top floor had been let a few months before to a tall man. With the usual vagueness of his type of mind, that was as far as he could go. Over and over again he repeated the same indefinite phrase, a tall man. When the man moved in, a couple of vans had brought strange furnishings, a small furnace, glassware and instrument cases. A little while ago an assistant had appeared, a foreigner who knew no English, or at least refused to understand the language. The two, the man and his assistant, often worked together till late at night. Sometimes, the clerk believed, they worked all night. As for him, he would have repeated the thing to the police. He didn’t believe in having mysteries like that around, but his master, the proprietor of the book shop, refused to part with regular paying tenants. Yes, sir, he’d tried again and again to see what they were doing, but there was a curtain over the door, and you couldn’t see anything through the keyhole. The door was always locked, so that the adventurous spirit of the clerk had to be content with imagining the horrible crimes perpetrated behind the curtained door.

This certainly looked good. With anxious hearts, Tom and I started up the stairs in search once more of our Cousin George, halting, however, at the second story, once the clerk was left safely behind.