Zuche: n. a tree stump
In the end, it was only a stump, but that did not matter. After all, they were only prisoners, and the whole scheme was based on making the extraordinary look unremarkable. And so instead of a door leading to a crevice in a hillside or something easy, they used a stump.
"Make this stump into a trapdoor," the Colonel said.
"I don't know… Do you know how hard it is to hide a seam like that?" Collins asked. The Colonel gave the carpenter a look that said he knew Collins could do it even so, and somehow, that was enough.