He turned on a big tap which was over the large sink. Then he took the handle of the pump and worked it vigorously up and down. Splash! Splash! Water came flooding through the big tap and splashed into the sink! That was good.

Julian pumped and pumped, feeling that he had better get rid of any water running into the tank for the first time for years. The tank might be dirty or rusty - he must wash it round with a good deal of pumped water first.

The water seemed to be clean and clear, and was certainly as cold as ice! Julian held a cup from the cellar cupboard under the tap, and then tasted the water. It was delicious.

“Good for you, Anne!” he called, going down the cellar-steps with a cupful of water. “Dick, you find some more cups - or a jug or something in that cupboard, and we’ll wash them out and fill them with water for our orangeade.”

The cellar room looked very cheerful as Julian came down the steps. George and Anne had lit six more candles, and stuck them about here and there. The light they gave was very pleasant, and they also warmed the room a little.

“Well, I suppose as usual, everyone wants a meal?” said Julian. “Good thing we bought that bread and potted meat and stuff. I can’t say I’m as hungry as I was at breakfast, but I’m getting that way.”

The four squatted round on their beds of heather and bracken. They had put down their ground-sheets first in case the floor was damp, though it didn’t seem to be. Over bread and butter and potted meat they discussed their plans. They would sleep there for the night and then have all the next day to examine Two-Trees and the lake.

“What exactly are we looking for?” asked Anne. “Do you suppose there’s some secret here, Julian?”

“Yes,” said Julian. “And I think I know what it is!”

“What?” asked George and Anne, surprised. Dick thought he knew. Julian explained.

“Well, we know that a prisoner called Nailer sent an important message by his escaped friend to two people - one he wanted to send to Dirty Dick - but he didn’t get it - and the other to Maggie, whoever she is. Now what secret does he want to tell them?”

“I think I can guess,” said Dick. “But go on.”

“Now suppose that Nailer has done some big robberies,” said Julian. “I don’t know what. Jewellery robberies probably, because they are the commonest with big criminals. All right - he does a big robbery - he hides the stuff till he hopes the hue and cry will be over - but he’s caught and put into prison for a number of years. But he doesn’t tell where the stuff is hidden! He daren’t even write a letter to tell his friends outside the prison where it is. All his letters are read before they leave the prison, So what is he to do?”