The Blackthorn Key

Cautiously, Tom held out a finger. He barely grazed the surface, then pulled away, leaving jittering waves that stilled almost immediately. He tried again, going deeper. “Strange. It doesn’t really feel like anything. It’s almost like it’s not even there. What’s it for?”


“Treating diseases. Really bad ones, that you get on your . . . you know. But what we want it for is . . . the key!” I turned the jar over.

Nothing happened.

“Do I applaud now?” Tom said.

I looked into the jar, frowning. “There’s nothing in here.”

“Why did you think there would be?”

“Because mercury is supposed to be the key.” I jiggled the cup, trying to see if anything had slipped out with the liquid. “That’s what quicksilver’s real name is. It’s called mercury. And that hole is where the planet Mercury would be.”

“That’s clever,” Tom said, looking at the cube, “but I don’t see how you’re going to get a key in here. The hole is too small. And it’s round. There’s no such thing as a round key.”

He was right. A round key didn’t make sense; it wouldn’t have any teeth. But Master Benedict had promised there was a key, and it was in this room.

That’s when it struck me. “Tom! You’re a genius.”

“I am?”

I pointed at the hole. “How would you get a key in there?”

“I told you, you can’t. It’s too small. You’d need something that could slip inside . . .” His eyes widened as I swirled the cup, sloshing the mercury around. “A liquid key? How is that even possible?”

“Let’s find out.”

He held the cube steady. Carefully, I tipped the cup. Three drips of liquid metal splashed onto the surface, running along the engraved circles like little silver beads. They drained toward the hole and slipped inside. Still, nothing happened.

“Maybe you need more,” Tom said.

I poured again, and a third time.

Click.

The seam around the top opened. Just a crack.

Slowly, I lifted the lid. I looked inside.

I gasped.





CHAPTER


6


TOM LEANED OVER. “WHAT IS it? What is it?”

I pulled it out and placed it on the counter.

It was a coin, shiny silver. Real silver.

Tom’s eyes bulged. “A shilling. You got a shilling.”

A shilling. Twelve whole pennies. I was rich.

The coin was brand new, the center stamped with a profile of the king. Around it was inscribed CAROLUS II DEI GRATIA. Charles II, by the grace of God. Oak Apple Day, his coronation day, his birthday. And mine.

I felt like I was glowing.

Tom picked up the shilling, marveling at it. I peered into the puzzle cube again. “Look at this,” I said.

The inside of the cube was antimony, too, except for one face opposite the hinge. Here it was glass, letting us see the lock’s mechanism. A channel from the top guided the quicksilver into a well in the front, where there was a lever. When we’d poured enough in, its weight pushed the lever down, which opened the latch.

“Brilliant,” Tom said.

It was, even more than it appeared. Master Benedict loved hiding things inside other things. Codes within codes, puzzles over locks. Here, too: inside my birthday gift, a second present. And beneath it all, a lesson in symbols.

No, I thought. Not just a lesson.

Last night, before he’d given me my present, Master Benedict had hesitated. He’d asked me if I wanted to stay with him, despite whatever danger he was in. Even when I told him yes, he’d hesitated. He’d prepared this gift for me, yet until that final moment, he hadn’t decided whether to hand it over.

The cube, the book, his words, this puzzle . . . it was more than a lesson. It was a test.

But of what?

I ran a fingertip along the grooves in the cube. Tom had said the thing was worth a fortune. I didn’t care about that. For whatever reason Master Benedict gave it to me, as a gift it meant so much more. I’d starve in the streets before I’d sell it.

“Wait here,” I said.