Canterstone Jail was an old-fashioned prison. In it each prisoner had two cells, one for the day and one for the night. The day-cells were on the ground-floor, those for the night were overhead. At six a.m. a bell was rung, and the warders unlocked the night-cells for the occupants to go down to those beneath. That was the rule. That particular morning was an exception to the rule. The bell was rung as usual, and the warders started to unlock, but there the adherence to custom ceased, for the doors of the cells refused to be unlocked. The night-cells were hermetically sealed by oaken doors of massive thickness, bolted and barred in accordance with the former idea that the security of prisoners should depend rather upon bolts and bars than upon the vigilance of the officers in charge. Each door was let into a twenty-four inch brick-wall, and secured by two ponderous bolts and an enormous lock of the most complicated workmanship. These locks were kept constantly oiled. When the gigantic key was inserted, it turned as easily as the key of a watch--that was the rule. When, therefore, on inserting his key into the lock of the first cell, Warder Slater found that it wouldn't turn at all, he was rather taken aback. "Who's been having a game with this lock?" he asked. Warder Puffin, who was stationed at the head of the stairs to see that the prisoners passed down in order, at the proper distance from each other, replied to him. "Anything the matter with the lock? Try the next." Warder Slater did try the next, but he found that as refractory as the first had been. "Perhaps you've got the wrong key?" suggested Warder Puffin. "Got the wrong key!" cried Warder Slater. "Do you think I don't know my own keys when I see them?" The oddest part of it was that all the locks were the same. Not only in Ward A, but in Wards B, C, D, E, and F--in all the wards, in fact. When this became known, a certain sensation was created, and that on both sides of the unlocked doors. The prisoners were soon conscious that their guardians were unable to release them, and they made a noise. Nothing is so precious to the average prisoner as a grievance; here was a grievance with a vengeance.