“Sums?” said Hypnos. “Sum of what? The squares?”

“I’m no good at maths, so I’ll leave you to—wait,” said Hypnos. He glanced down at his feet at the same time that Enrique felt a curious suctioning on the bottom of his boots. The sunken ground of the grave had started to pull them in bit by bit. Hypnos shrieked and tried to lift his leg, but it was stuck fast in the earth. Enrique gripped the tombstone, trying to haul himself out, but that only made the Forging mechanism work faster. Within seconds, he was up to his knees. The light around them leapt wildly, swinging from the grave to the tombstone and the flat eyes of the two-headed god. Enrique wrenched around to see Zofia jumping for a branch in the cypress tree to pull them out, but the branches were too high—

“Hurry!” said Hypnos. “Put in the answer! It’s nine, isn’t it? Just do it!”

Enrique dragged his fingers across the stone, his heart sinking.

“Nine isn’t an option! Maybe it’s ten because the whole thing is an additional square?” he said.

But when he looked at the numbers, there was no zero either. Panic laced up his spine.

“Six?” tried Hypnos.

“How could there be six?!”

“I’m no good at maths!” shouted Hypnos.

“I couldn’t tell!”

The grave dirt made loud squelching sounds, seeping through the buttons of his shirt front and pouring cold across his skin. Enrique tried to kick his feet, only to feel something hard and smooth slide along his calf. On instinct, he recoiled, which only dragged him down farther. Enrique scrambled to hold on to solid earth, but all of it turned soft and sinking to the touch. Hypnos started whimpering, but Zofia shouted out:

“One and four!”

“That makes no sense!” said Hypnos. “Maybe it’s only one large square and it’s just a terrible joke…”

Enrique studied the grid. Nine squares. One big square encompassing it … and four squares made up of four blocks within the pattern. 14.

With shaking hands, he tapped the number 1 and then hit the number 4. The numbers depressed farther into the rock as the earth pulled him down farther. Cold mud pooled around his shoulders when light abruptly flashed across his eyes.

The sinking stopped.

“Thank gods!” screamed Hypnos, hoisting himself out by his elbows. Enrique grabbed fistfuls of earth, dragging his body halfway out. Hypnos and Zofia reached for his hands, pulling him the rest of the way until he could slump onto the land, breathing hard.

“The—key—” he managed, facing the tombstone.

The Forged stone had contorted once more. Now, an address appeared on it:

Calle Tron, 77

A large key, the kind that might unlock a manor in the countryside, bubbled up out of the stone. Enrique stared at it in wonder. He felt Hypnos clapping his back enthusiastically and heard Zofia demanding that they leave now, and hope swelled in his chest.

The key to the safe house was not the solution to everything. They still needed to find the map to the temple beneath Poveglia. They still needed to play the lyre and save Laila’s life. And Enrique still did not know where he belonged … but he felt a little surer at the front of the group as he turned to them and said: