The door to this was closed, a bolt on the inner side holding it in place.

There was another bolt on the outside, which Dick remembered having seen on a previous visit.
"We can lock them in if we wish," he whispered.
"Do it," answered his brothers promptly.
The bolt was large and old fashioned, and Dick had considerable trouble in moving it into its socket.

It made a rasping sound, but this was not noticed by the two men, who were conversing earnestly.
"Well, we made a mess of it," growled the man called Shelley.
"So we did.

But I didn't think that hired man would wake up.

Neither of us made a bit of noise.