I was coming through the window when I heard your voice at the door!" Bailey's eyes leaped to the window--yes--a ladder was there--the Doctor might be speaking the truth after all.

But if so, how and why had Dale disappeared?
The Doctor's admission of his manner of entrance did not make Lizzie any the happier.
"In at the window--just like a bat!" she muttered in shaking tones.
She would not have stayed in the doorway if she had not been afraid to move anywhere else.
"I saw lights up here from outside," continued the Doctor easily.

"And I thought--" Miss Cornelia interrupted him.

She had set down her candle and laid the revolver on the top of the clothes hamper and now stood gazing at the mantel-fireplace.
"The mantel's--closed!" she said.
The Doctor stared.

So the secret of the Hidden Room was a secret no longer.