Daniel bristled at the autocratic tone. “I have spoken with Miss Montgomery, and the documents will be returned to her when the investigation concludes. I appreciate that you have a job to do, but so do I. We’ll go over the financials and correspondence as quickly as we can, but it will take some time.”

He turned away from the fussy accountant and addressed the scientist, who continued to hop from place to place like a flea. “Are you certain the explosion was an accident, not executed to cover up Mr. Montgomery’s murder? That the timing was a coincidence?” Daniel rubbed his hand on the back of his neck.

“If it was done to cover up the murder, it was singularly unsuccessful, wasn’t it? You were able to identify the owner as having been killed by something other than the blast, were you not?” Rhynwick asked, as if Daniel were as simple as a pudding.

“He was shot through the head.”

“I wish I had been able to examine the body in situ.” He traveled the length of the hallway again, hands clasped behind his back, his shoes coating with ash and his trouser cuffs stirring the dust. “I might have been able to tell you more.” He shrugged. “As it is, I shall take my leave. I have some experiments brewing that need tending. I shall be in touch, Mr. Hoffman.”

“Wait! Do you have a card?” Daniel asked. Such a bright young mind could be useful in future cases.

“Hoffman knows where to find me.” And like a linnet, he was away. Daniel almost imagined he could hear the flutter of wings.

“A most interesting fellow,” Ed commented, a bemused look on his face. Mostly he had stood back and observed, and Daniel looked forward to hearing his thoughts.

“A child, that’s what.” Mr. Earnshaw wrung his hands. “We’ve never had a flour dust explosion here. That should prove him wrong. If this place was prone to such a thing, wouldn’t it have gone up before now? It was the work of someone who did not wish Mr. Montgomery to proceed with his plans for the mill. They shot him and set fire to the mill on purpose to stop the changes.

“Mr. Montgomery was afraid something like this would happen when he started receiving those threatening letters, and it finally did. I only wish I could have prevented it.” He touched the still-healing wound at his hairline. “It’s only the grace of God that I wasn’t killed too.”

“Have you managed to find those letters? You mentioned them once before and said you would bring them to Bow Street.” Daniel moved Montgomery’s office door, which had been sprung on the hinges and dragged on the floor with a wince-inducing squeal. “We’ve taken a cursory glance through most of Montgomery’s papers salvaged from here, and we’ve found no indication of a threat.”