The path ran close to the pond in the shadow of a great tree. In the greater gloom under the branches, Tom slipped on a patch of ice. He fell, measuring his length on the stones. The barrow toppled on to the frosty grass and discharged at least half of its stinking cargo on the bank. The shovel, which had been balanced on top, slithered into the water.

Panting with cold, he righted the trolley. He would have to clear as much as he could of the filth, and hope against hope that rain would wash the rest away before anyone noticed it. But the shovel was somewhere in the pond, and he could do nothing without it. Surely the water near the bank could not be very deep? He took off his brown coat and rolled the sleeves of his shirt above his thin, pointed elbows. He was about to plunge his hand into the water when he saw a large, dark object floating among the shards of thin ice a yard or two from the bank.

At first he thought a sheet or a shirt had fallen into the pond, for the east wind had blown strongly during the last few days, often coming in savage gusts. The following instant he thought of a more interesting idea – namely, that the floating thing was a cloak or gown discarded by a reveller during some drunken prank the previous evening. He had retrieved caps and gowns from cesspits on several occasions and either restored them to their owners or sold them to a dealer in second-hand academic dress.

Tom Turdman thrust his right arm into the freezing water. He whimpered as the cold hit him. To his relief, his fingers closed around the shaft of the shovel. All this time his mind was partly distracted by the risk of Mepal’s vengeful anger if he discovered what had happened, a risk that grew with every minute’s delay.

The sky was becoming paler. But the goddamned tree blocked so much of the light. He straightened up and stared at the thing in the water. If it was a cloak or gown, it held the possibility of substantial profit.