The Blackthorn Key (17 page)

I knelt, searching. I didn't see any seams around it, any brick to move. I ran my fingers along the symbol, tracing the ripples of lightly corroded stone all the way around. The groove fit the circle perfectly.

I pressed it. The loop of stone slid in.

There was a low
click
.

A hollow grinding echoed in the chamber. I fell back, Tom pulling me by the collar. Bridget flapped her wings and flew for the light.

The sarcophagus shifted three inches toward Saint Jerome. Then it stopped.

Below the casket, dug in the floor, was a hole.

I PEERED INTO THE DARKNESS.
It smelled musty.

“This is bad,” Tom said.

“This is good,” I said.

Tom shook his head. “I'm pretty sure this is bad.”

I couldn't see anything, but the way the hole swallowed my voice made it clear that whatever was down there, there was a lot of it. There had to be a way to fit inside.

Bridget came back and peeked into the hole. I nudged her aside and pushed the casket toward Saint Jerome. It slid another inch. “Help me.”

Reluctantly, Tom came over and gave the sarcophagus a
shove. It ground against the floor until it stopped with a jolt. The hole underneath was square, three feet wide. On the side nearest the angel, a notched wooden ladder descended into the dark.

“We need light,” I said.

“We're not going down there,” Tom said.

“But this is what we came here for.”

Tom threw his hands up. “I didn't know there'd be a pit under a coffin.”

An unlit torch hung in the corner by the door. I used the flint and tinder from my master's sash to ignite its oil-soaked end.

The torch flared brightly in the cramped chamber. I held it over the hole and was barely able to see the bottom.

“About twenty feet,” I said. “Come on.”

I swung onto the ladder. Bridget marched around the hole, poking her head in and ruffling her feathers. She trilled, alarmed.

“Listen to the bird,” Tom said.

I went down. The air grew noticeably more damp with each rung. Grumbling, Tom followed. Bridget flapped her wings at me, but she wouldn't come.

We were in what looked like an ancient crypt. The
passage, eight feet wide, tracked away from the ladder, back toward the house. On either side, in narrow ledges dug into the rock, were skeletons.

Tom stepped off the ladder. “Oh, of course there are bodies.”

The remains had clearly been here for ages. Their clothes and wrappings had disintegrated, leaving nothing but the occasional rusted buckle among time-stained bones.

“This crypt must have been built centuries ago,” I said. “Let's see where it goes.”

Tom clasped his hands together and mumbled a prayer. “Jesus, in Your mercy, please protect fools like us. Amen.”

The passage continued, skeletons lining the sides, for about fifty feet before it turned sharply to the left. It narrowed, just enough to fit a man, then widened into a smooth, square chamber.

Unlike in the passageway, the items in here were new. On both sides were workbenches. The one on the left held about thirty glass jugs, each one labeled with a liquid: water, mercury, aqua vitae, oil of antimony, and more. The other bench supported an equal number of smaller glass jars, also labeled, containing powders. Salt, natron, sand, clover, all familiar. But what really drew my eye was what faced us.

The wall opposite the entrance was covered with a mural. At the top, an angel drove his sword downward into the belly of a dragon. The dragon twisted and writhed, roaring in agony, about to gobble a small black ball. Below the beast were two more dragons, their own serpentine bodies coiled, each snapping at a ball identical to the one above. The scene was ringed by an enormous snake with a red back and a green stomach, its head above the angel's, swallowing its own tail.

Tom yanked at my sleeve so hard, he nearly tore my shirt. “We have to go. Christopher.
We have to go
.”

I could barely keep my balance. “What are you doing?”

“Don't you realize where we are? This is the lair of the Cult of the Archangel.”

“It isn't,” I said.

Tom stabbed a finger at the mural. “Cult.” Then he pointed at the figure at the top. “Archangel.” He shook me. “Now put them together. How hard is that?”

“This can't belong to the Cult,” I said. “Master Benedict wanted me to find this. He wouldn't send us into the lair of his killers without any warning.” I would never believe that.

Tom wasn't as confident, but at least he stopped trying to tear my arm off. “Then . . . what is this place? Some sort of secret apothecary workshop?”

“It's not a workshop.” Other than the ingredients in the jars, there wasn't any equipment. There were just a couple of glass beakers with long narrow spouts on the table with the liquids, and a long-handled metal spoon on the other. “It looks like a storeroom.”

“For what?”

I wasn't sure. There were a lot of ingredients, but nothing you wouldn't find in any apothecary. I couldn't imagine why anyone would hide them down here.

Tom, still staring at the mural, pulled me close and whispered in my ear. “But what if we're being watched?”

“Tom,” I said. “It's a painting.”

“Then what are the holes in it for?”

For a moment, I had no idea what he was talking about. Then I realized he was right.

The black spots, in the dragons' mouths. I'd thought they were paint, like the rest of the mural. But up close, I could see each one was actually a small hole in the wall, the three of them together forming the corners of a perfect triangle. I peered into the one being eaten by the dragon on the left, but even with the torch, it was too dark to see anything. Against Tom's urging, I poked my finger inside.

I couldn't feel anything, either. There was a gap behind the wall, but the end—if there was one—was at least far enough away that my finger couldn't reach it. I could tell one thing, though. From the smoothness of the hole, and its coolness on my skin, the wall wasn't stone. It was iron.

Up close, the mural was even more remarkable. Hundreds of shapes and symbols were inscribed around the dragons. Some were simple, like circles and squares. Others looked more like alien letters of a forgotten language. As I stared at them, I noticed something. Near each of the holes in the dragons' mouths, some of the glyphs were ringed with gold, so faint you could barely see it.

Gilded next to the serpent at the top was a triangle with a line across it, like the peak of a snowcapped mountain.

The dragon in front of Tom had three highlighted symbols: a triangle, upside down; a curious ladder with a strange zigzag at the bottom; and a circle with a horizontal line through its center.

The final dragon, in front of me, had a single golden glyph.

I stopped. I'd seen this one before.

This was the symbol for the planet Mercury. I looked back at the workbenches, and the ingredients that sat upon them. I took my puzzle cube out of my pocket and turned it around.

“What is it?” Tom said.

I touched the wall. “I think I know what this is. It isn't just a painting.” I traced my fingers from the dragon to the hole. “I think this is a
door
.”

TOM INCHED AWAY FROM THE
mural. “A door?”

I pointed to the symbols above the holes. “I think this is what the ingredients on the tables are for. The liquids and powders, the beaker, the spoon. It's like my present.” I held out the antimony box. “You pour the right thing in and it opens.”

“What's the right thing?”

“Well, this symbol here is for Mercury, so I'm guessing it's quicksilver.”

There was plenty of mercury in one of the jars on the table, more than I'd ever seen in one place before. I took one
of the notched beakers and poured some of the quicksilver into it. The glass grew heavy as I filled it to the mark.

At the door, the beaker's nozzle fit cleanly into the hole in the dragon's mouth. I tilted it, letting the metal run out. With the last few drops, a faint
thunk
came from behind the mural.

“It worked,” Tom said.

But nothing else seemed to happen. I pushed on the wall. Tom joined me, putting his shoulder to it. It didn't budge. We heard another
thunk
, as if something clicked back into place.

I stepped away from the mural. “There are two more holes,” I said. “We must have to put something in all of them to open the door.” And from the sound of it, we didn't have much more than a minute to make it happen.

The symbols, with the right ingredients, were the key. I was amazed at how clever this was. It was much better than an actual key of iron or brass, which could be lost or stolen. With this door, if you were allowed in, you'd already know how to enter. Which we didn't.

“What about the rest of the message?” Tom said. “Those letters, from the code in lemon juice. Maybe they tell you what the ingredients are.”

I pulled the parchment with the code from my pocket.

JSYYAALYUFMIYZFT

“Look,” Tom said. “Say the
M
is for ‘mercury.' Then
J
is for . . . uh . . . ‘jam.' Or something.”

If you ignored the part about jam, Tom's idea was a good one. But there were two more holes, four more symbols, and my master's message had enough letters to start a new alphabet. Even if Tom was right, I couldn't count how many different combinations we'd have to try. We were lost.

Again.

•  •  •

We returned to the surface and pushed the sarcophagus back into place. Bridget had already gone. Though I wanted desperately to remain below a little longer, I couldn't stay either. The afternoon was passing quickly, and I needed to get back to Apothecaries' Hall.

We stopped at Tom's house on the way. Reluctantly, I left the puzzle cube in his room. My master's sash could be more or less hidden under my shirt, but the cube was too bulky to carry well concealed, and the last thing I needed was Grand Master Thorpe asking what was in my pocket. I did keep the ledger page and the scrap with the
translation, which I tucked safely underneath the sash.

As we left Tom's bedroom, Cecily appeared in the doorway to hers. Her eyes were wide with fear.

“Run!” she whispered.

Little Molly slipped past her sister, her mop of curls bouncing as she ran. She threw her arms around me, buried her face in my stomach, and sobbed.

I looked at Tom, puzzled. He knelt beside his sister. “Molly? Cecily? What's wrong?”

A meaty fist grabbed the back of Molly's dress and pulled her away. She landed on her backside, wailing.

Tom looked shocked. “Father!”

William Bailey grabbed me, next. I'd never been dragged by my hair before, much less while bumping down a flight of steps. Catherine and Isabel, playing in the front hall, dropped their dolls and scrambled behind their mother, who watched her husband pull me away.