The scientific mind is equal to every emergency.

'Bradshaw,' shouted Blaize through the keyhole.

'Sir?'

'Are you there?'

I should imagine that Bradshaw was growing tired of this question by this time. Besides, it cast aspersions on the veracity of Gerard and Mellish. Bradshaw, with perfect politeness, hastened to inform the gentleman that he was there.

'Have you a piece of paper?'

'Will an envelope do, sir?'

'Bless the boy, anything will do so long as it is paper.'

Dear me, I thought, is it as bad as all that? Is Blaize, in despair of ever rescuing the unfortunate prisoner, going to ask him to draw up a 'last dying words' document, to be pushed under the door and despatched to his sorrowing guardian?

'Put it over your hand, and then shoot back the bolt.'