I entered the vault, pausing to listen for any sounds indicating security systems. There was a hum from fluorescent lights overhead, and the soft whoosh of an air system pumping air into the large vault. Ahead of me were long rows of metal cases. I touched the nearest one, but there was no lock on it. I slid the door out and rolled it back along a track. Boxes labeled ‘‘Grimoires, 1450 to 1800’’ filled the cabinet. The next one housed a collection of spell books. I closed both and moved down the line of cabinets. The vault was evidently created from the original storerooms of the cellar, separated by modern metal doors. Careful to avoid making any sound, I gently persuaded the door’s lock to bend to my will, slipping silently through the doorway and closing it with only the barest whisper of noise.

The spotlight hit me almost at the same time as the sound.

‘‘Aaaaaand . . . two, three, four!’’

A chorus of reedy voices began to sing to an accompaniment of tinny music. Startled by the lights and noise, I shadowed immediately, although I was sure I was visible under the bright light that filled the room. Momentarily blinded, I strained my eyes to see even as I sidled out of the way of the spotlight.

‘‘No, no, no!’’ The words were punctuated with a slapping noise. I blinked a couple of times, my vision slowly adapting to the light. What I saw left me speechless with amazement. The room held the same gray metal cabinets as the previous room, but these ones lined the walls rather than filled the floor space. That was taken up by a large wooden desk—or I assumed it normally would have been the case, the desk currently having been shoved to a far corner. Also dotted around the perimeter of the room were a couple of tall standing lights, the kind used by smaller theater companies. But it wasn’t any of that which made me gawk.

‘‘You have to listen to the beat! Move to the tempo! For the sovereign’s sake, you’re Munchkins, not lumbering baboons! It’s not . . . that . . . hard!’’ The last three words were punctuated with the slam of a ruler against the wooden desk. A man yielded the ruler— at least I thought at first it was a man, but as I watched in openmouthed amazement, I realized he was slightly translucent. A spirit, then, not a man. Which meant . . . I turned my gaze to the center of the room.

Six imps stood in a row, clad in sequin-bedecked costumes that had only a passing resemblance to those worn by the Munchkins in The Wizard of Oz.

‘‘Now we will try this again, and this time, listen to the blasted music! Everyone lift your right foot. That’s your left hand. Lift your right . . . oh, let me show you. Again.’’