The Amulet of Samarkand

Shield, which repelled Jabor's steadily weakening Detonations and spun them away around the room. At last a horla won free of the portal and, with his armor fully formed, came creeping round the edge of the Shield. Jabor fired at him; the blast hit the horla in his spindly chest and was completely absorbed. The horla gave a wintry smile and darted forward, spinning his net like a bola.
    Faquarl became a raven and took off effortfully, one wing laboring through the air. My falcon followed him, up toward the hole. A net passed just under me; a trident buried its prongs in the wall.
    "Jabor!" Faquarl shouted. "We're leaving!"
    I snatched a look below: Jabor was grappling with the horla, his strength seemingly undiminished. But countless more kept coming. I concentrated my efforts on reaching the hole. Faquarl had already vanished within it; I ducked down my beak and plunged in too. Behind me, a colossal explosion rocked the room and I heard the savage fury of the jackal's cry.
    In the narrow, pitch-black tunnel, Faquarl's voice sounded muffled and strange. "We're nearly out. Being a raven would be most appropriate from now on."
    "Why?"
    "There are dozens of the things out there. We can mingle with the flock and gain time while we make for the walls."
    Loath as I was to follow Faquarl's advice about anything, I had no idea what we were up against outside. Escape from the Tower was the priority. Escape from him could come later. So I concentrated and shifted form.
    "Have you changed?"
    "Yep. It's not a guise I've tried before, but it doesn't seem too difficult."
    "Any sign of Jabor behind us?"
    "No."
    "He'll be along. Right, the opening to the outside is just ahead of me. There's a Concealment on the exit hole, so they shouldn't have spotted it yet. Fly out fast and go straight down. You'll see a kitchen yard where the ravens congregate to gather scraps; I'll meet you there. Above all, don't be conspicuous."
    A scrabbling in the tunnel ahead, then a sudden burst of light. Faquarl was gone, revealing the outline of the exit, covered with a mesh of concealing threads. I hopped forward until my beak hit the barrier, pressed against it and pushed my head through into the cold November air.
    Without pause, I pushed off from the hole and began to glide toward the courtyard below.
    As I descended, a brief glance around confirmed how far I was from safety: the distant rooftops of London were barely visible behind a series of rounded towers and curtain walls. Guards walked upon them, and search spheres moved randomly through the sky. The alarm had already been raised. From some eyrie high above, a siren was wailing, and not far off, within this innermost courtyard, battalions of police were running toward an unseen point.
    I landed in a little side yard, cut off from the general panic by two outbuildings that projected from the body of the main tower. The cobbles of the yard were covered in greasy scraps of bread and bacon rind, and by a hungry, cawing flock of ravens.
    One of the ravens sidled over. "You idiot, Bartimaeus."
    "What's up?"
    "Your beak's bright blue. Change it."
    Well, it was my first time as a raven. And I'd had to alter in the dark. What did he expect? But it wasn't the time or place to argue. I changed the beak.
    "They'll see through the disguise anyway," I snapped. "There must be a thousand sentries of one sort or another out there."
    "True, but all we need's a little time. They don't know we're ravens yet, and if we're in a flock, it'll take them a few extra seconds to pick us out and check. All we need now is for the flock to fly...."
     
    One moment a hundred ravens were snapping innocently at cold bacon rind, at peace with themselves and the world. The next, Faquarl revealed his true self to them on the first plane: he only did so for a fraction of a second, but the glimpse was enough. Four ravens dropped dead on the instant, several others lost their breakfast, and the rest took off from the courtyard in a panic-stricken mob, cawing and clawing at the air. Faquarl and I were in the heart of the flock, flapping as hard as we could, wheeling and diving when the others did so, desperately trying not to be left behind.
    Up high and over the flat roof of the great keep, where a huge flag fluttered and human sentries stood gazing out across the waters of the Thames; then down low and sweeping across the gray courtyard on the other side. Around twenty permanent workaday pentacles had been painted in the center of