My problem was a lack of understanding about how a screw joint actually works. It's not the threads biting into both pieces that secured everything in place. Rather, the strength of a screw joint comes from the threads pulling the screw through the bottom
TreeHugger has shown many ways to hide the bed; most are designed to gain more space. But the Red Nest by Paul Coudamay doesn't; the bed is still there taking up space, but is hidden by the sliding bookcase.