fastening. "You didn't use that larger lock?"

"No. I haven't for months. The key is lost, I think."

Retracing his steps the investigator sighted the hole from the
radiator, and shook his head.

"It's not in range," he said. "Go on."

"As I reached the door on my return, I heard Rags yelp. You may
believe I got to him quickly. He was pawing wildly at his nose. I
called up the nearest veterinary. Within ten minutes the
convulsions came on. The veterinary was here when Rags died, which
was within fifteen minutes of the first spasm. He didn't believe it
was strychnine. Said the attacks were different. Whatever it was,
I couldn't find any trace of it in the stomach. The veterinary took
the body away and made a complete autopsy."

"Did he discover anything?"

"Yes. The blood was coagulated and on the upper lip he found a
circle of small pustules. He agreed that both dogs probably
swallowed something that was left in my office, though I don't see
how it could have got there."

"That won't do," returned Average Jones positively. "A dog doesn't
cry out when he swallows poison, unless it's some corrosive."

"It was no corrosive. I examined the mouth."