He could hear them muttering to each other in low voices. One of them sounded frustrated, probably suspecting the noise had been nothing more than an accident or a stray cat knocking something over. They hesitated for a moment longer, then resumed their cautious approach toward the gallery.
Henry let out a silent exhale, and with one last glance over his shoulder, pressed the silent alarm button beneath the counter. A small, satisfying click confirmed the signal was sent, triggering the lockdown of high-value rooms and sealing each display case.