Breaching the perimeter

The glass panel lacked a latch, but the upper rim had a hairline gap. I braced both boots against the diorama's resin rock face, testing the friction. Firm enough. Reaching upward, my gloved fingers found purchase on the edge. A steady lever of weight, and the transparent pane slid two inches along its wooden groove. Just enough clearance. I dropped onto the polished mahogany desk without a sound. Beside me lay an unrolled street map of Buenos Aires held flat by a brass paperweight. I surveyed the desk's dark expanse, noting a desk lamp above and a drop of three feet to the floorboards. Ground gained.