So far, so good!
He whispered to Joe.
"All right. Come ahead."
In the aperture in the roof he could see Joe's form silhouetted, and then his brother scrambled down beside him in the attic.
"I've found a trapdoor," Frank whispered.
"Where does it lead to?"
"There's another room directly below us. It's empty. The workroom must be just below that. But there's a door at the far side of the room, and I think it leads to the stairs that run to the bottom of the mill."
"Shall we go ahead?"
"May as well. We haven't been seen yet. Nor heard."
Frank handed the flashlight to his brother, then groped his way to the trapdoor. He managed to place one foot on the top rung of the ladder beneath the opening.