The electric space heater in the Strasburg site barn gave off a low, humming buzz at eight the next morning.

Martha stood on a wooden crate near the back wall, lifting an eight-foot sheet of moisture-resistant drywall against the wall studs with her shoulder while holding a screw gun in her right hand.

Nathaniel watched from the doorway as she drove three screws into the center metal stud without letting the board drop a fraction of an inch.

Her wrist moved in a steady, automatic rhythm, spreading joint compound so thin over the recessed edge that the paper tape barely showed underneath.

“Where did you learn to feather a joint like that?” Nathaniel asked, walking over to the folding work table, where blue site drawings lay unrolled under a steel square.