After a cave-in decades ago had compromised its structural stability, the quarry had been shut down, and the whole site abandoned due to rising extraction costs and falling demand. The administrative offices and the workshops where the ore had been refined were enormous, drab constructions typical of the Fascist period, their straight lines, smooth surfaces, and confined spaces indicating a fixation with grandeur manifesting itself—in the midst of that natural landscape—as a blight on the face of the earth.

The entrance to the mine was blocked off by a wire fence. The chain that had once fastened it to a set of hooks embedded in the rock had fallen to the ground, corroded by rust. A line of footprints in the snow led into the darkness beyond.

Teresa ordered the fence pushed aside and peered into the gloom. She shone her flashlight into the tunnel, illuminating a set of railway tracks inside.

“The temperature in there is constant throughout the year, around nine degrees, with humidity levels at ninety-eight percent,” Knauss informed her.

De Carli and Parisi arrived.

“Have you brought what I asked for?” she said.

“Yes, Superintendent.”

Teresa checked that she’d turned her phone off, before putting on her fluorescent yellow vest and a hard hat mounted with a headlamp. This time, she would be the one to take the lead.

“What if it’s another red herring?” said Knauss.

Teresa had been asking herself that same question ever since she’d decided to concentrate all their efforts here, but she kept thinking they had nothing left to lose—there were no other leads to follow.

She stared into the darkness again, at those footprints leading into the belly of the earth. Perhaps they were old. Perhaps they belonged to someone else. And still, the only sound they could hear from the depths of the tunnel was the monotonous dripping of water.

“I told you,” said Knauss, spitting on the ground. “He wouldn’t have made it all the way here.”

“Make him shut up,” Teresa whispered to De Carli.

“We’re wasting our time, I . . .”

Teresa—who was shorter than him, weaker than him, and yet determined to emerge victorious from this new confrontation—grabbed him by the lapels of his coat.

“You didn’t tell me about the protesters, you didn’t tell me about Ebran, and you didn’t tell me about these tunnels,” she said, her voice quiet but shaking with rage. “You’re lucky, Chief Knauss, that I don’t have time to deal with your incompetence right now. But rest assured, that moment will come. I truly hope we find what we are looking for when I walk in there, because that would mean three things: one, that we’ve rescued the child; two, that we’ve caught the killer; and three, that we’ve shown once more to those who need to know how utterly superfluous you are to the police force.”