A fierce effort thrust the rusted knob inwards, releasing a huge spout of water into his face from the dragon's gaping throat. The fountain, dry for many years, soared rejoicingly heavenwards, drenching the treasure-hunters, and making rainbows in the moonlight.

"I suppose this is 'Old Cut-throat's' idea of humour," grumbled Wimsey, retreating cautiously round the dragon's neck. "And now I can't turn it off again. Well, dash it all, let's try the other eye."

He pressed for a few moments in vain. Then, with a grinding clang, the bronze wings of the monster clapped down to its sides, revealing a deep square hole, and the fountain ceased to play.

"Gherkins!" said Lord Peter, "we've done it. (But don't neglect bailing on that account!) There's a box here. And it's beastly heavy. No; all right, I can manage. Gimme the boat-hook. Now I do hope the old sinner really did have a treasure. What a bore if it's only one of his little jokes. Never mind—hold the boat steady. There. Always remember, Gherkins, that you can make quite an effective crane with a boat-hook and a stout pair of braces. Got it? That's right. Now for home and beauty.... Hullo! what's all that?"

As he paddled the boat round, it was evident that something was happening down by the boat-house. Lights were moving about, and a sound of voices came across the lake.

"They think we're burglars, Gherkins. Always misunderstood. Give way, my hearties—

"A-roving, a-roving, since roving's been my ru-i-in,

I'll go no more a-roving with you, fair maid."

"Is that you, my lord?" said a man's voice as they drew in to the boat-house.

"Why, it's our faithful sleuths!" cried his lordship. "What's the excitement?"