I stopped at the stairhead and faced him.

"I cannot suppose that you are joking, Smith," I said, "but--"

He laughed dryly.

"Forgive me, old man," he replied. "I was so preoccupied with my own
train of thought that it never occurred to me how absurd my request
must have sounded. I will explain my singular tastes later; at the
moment, hustle is the watchword."

Evidently he was in earnest, and I ran downstairs accordingly,
returning with a garden trowel, a plate of cold fish and a glass of
milk.

"Thanks, Petrie," said Smith--"If you would put the milk in a jug--"

I was past wondering, so I simply went and fetched a jug, into which
he poured the milk. Then, with the trowel in his pocket, the plate of
cold turbot in one hand and the milk jug in the other, he made for the
door. He had it open when another idea evidently occurred to him.

"I'll trouble you for the pistol, Petrie."

I handed him the pistol without a word.

"Don't assume that I want to mystify you," he added, "but the presence
of any one else might jeopardize my plan. I don't expect to be long."