“I want that axe you use for felling big trees,” he added.

The man went to the tool-shed in wonder, and placed them in the car.

Then all four set out in the rain upon a strange and exciting expedition.

The note had been picked up not far from the ruined mill on the bank of the river Wey. From Roddy’s message it seemed to the girl that he must certainly be held prisoner within that old mill, so they drove away along the London road through Godalming and Guildford until they found themselves at Woking Station. Then on inquiry, and after losing themselves three times on narrow, intricate roads, they at last came to the bank of the river, a tributary of the Thames, and presently found the dark walls of the half-ruined mill.

On pulling up Elma shouted with all her might.

“Roddy! Roddy!”

There was no response. They saw in the darkness that the river was swollen and was running swiftly towards the Thames.

“Roddy! Roddy!” the girl shouted again, whereupon at last there was a very faint response, deep down somewhere. All were silent for a few seconds.

“By Gad!” cried Mr Sandys, “he’s here! Yes. He’s here!”

The two servants got out the axes and crowbars and, aided by their master, attacked the heavy iron-bound door of the disused water-mill. At first it resisted them. It was of oak and centuries old, as was the stone structure itself.