“Or fallen in.”

A little way within the park we found the steep-sided channel of the brook which flowed across the farm of the sisters Delambre, later on passed beneath the elaborated bridge, and eventually joined Aidenn Water. The bank at this point was five or six feet high.

“What next?”

Aire slid and floundered down to the edge of the rivulet which whispered along the channel.

“Can’t tell for certain, but I believe it went toward the bridge.”

I got down beside him, and we sped between the banks, which gradually lifted above us. Dry land was scarce, and we did a deal of splashing in the brook, but by the aid of my torch I seemed to see ahead muddy traces of other splashing before ours. A wild rose growing on the edge of the water had been trampled down.

A couple of short turns in the course of the brook brought us to the stone bridge, a structure magnificently heavy in the body, but leaving a semicircular arch only about eighteen inches high for the passage of water.

“It’s a blind alley. No man—or woman—could have gone through there. There isn’t room for a good-sized dog.”

I bent down and shot the light underneath; there was nothing but water there.

“Well—”