You can see by a glance through the windows that they also are closely guarded.

Escape is impossible.
In half an hour I will knock upon the door, open it, and escort you back to your place of confinement.

Do you understand ?" "Perfectly." "Enter." Somewhat bewildered by the mysteriousness of the whole proceeding, and yet with a heart which in spite of himself did beat a little faster, Marteau entered the room, St.Laurent closing the heavy door behind him..