“Oh, sir — then won’t you just take a torch and look round the place?” begged Jenny. “You know there’s your precious papers in that tower, sir. And isn’t there that new invention of yours? Oh yes, I know I’m not supposed to know anything about it, sir, but I do dust your rooms thoroughly, you know, and I see quite a lot, though I keep my mouth shut, and…”

“Yes, yes, Jenny, I know,” said poor Professor Hayling, trying to stop Jenny’s stream of talk. “But honestly, everything seems quiet now. I’ve looked out into the courtyard. There’s no one there. And you know as well as I do that nobody can get into my tower. It has three different keys — one to unlock the bottom door — one for the middle door, half-way up — and one for the top door. Jenny, be sensible. Nobody could have used my three keys. Look, there they are on my dressing-table.”

Jenny began to calm down, but she still wasn’t satisfied. “I did hear whispering, and I did see someone half-way up the wall of the tower, sir. Please do come down with me, sir, and let’s look around. I daren’t go on my own. But I shan’t sleep again tonight till I know nobody’s forced the tower door, or taken a ladder to go up the tower.”

“All right, Jenny,” said the Professor, with a sigh. “Put on your dressing-gown, and I’ll put mine on too — we’ll try the doors, and we’ll look for a ladder — though, mind you, it would have to be an absolutely colossal one to reach the top of that tower. Nobody could possibly bring one that size and length into our small courtyard! All right, all right — we’ll go.”

And so, a few minutes later, Jenny and the Professor were down in the courtyard. There was no sign of any ladder at all — no sign of anyone climbing up the wall-and the downstairs tower door was safely locked! “You unlock the door, sir, and go up to the top room and see if that door’s locked too,” begged Jenny.

“I think you’re being rather silly now, Jenny,” said the Professor impatiently. “Here, take the keys yourself. This one’s locked, of course — and if the middle door is still locked, you’ll know nobody could have got into my top room. Hurry, Jenny.”

So Jenny, still trembling, slid a key into the bottom lock, opened the door, and began to climb the spiral stair that led upwards. Half-way was another door, also safely locked. She unlocked this too. She began to feel rather silly. Nobody could have gone through locked doors. And there now — the top one was well and truly locked also! She gave a sigh of relief and ran down the spiral stairway, locking the middle door, and then the bottom one. She gave the keys to the Professor, who by now was feeling rather chilly!

“All locked, sir,” said Jenny. “But I’m still sure someone was about. I could have sworn I saw someone up that tower-wall, and heard somebody else whispering below.”