The study--that most remarkable of rooms--contains a secret which has not been imparted to you; a very peculiar one, madam, which was revealed to me in a rather startling manner.

This room can be, or rather could be, cut off entirely from the rest of the house; made a death-trap of, or rather a tomb, in which this incomprehensible man may have intended to die.

Look at this plate of steel.

It is worked by a mechanism which forces it across this open doorway.

I was behind that plate of steel the other night, and these holes had to be made to let me out." "Ha! You detectives have your experiences! I should not have enjoyed spending that especial evening with you.