Teresa looked at her watch and recalled how Roberto Valent’s had been tied to the effigy’s arm the wrong way around. She still hadn’t figured out what that meant. There were only a few hours left now until dawn, when they could get started with the search. They just had to hope the weather worked in their favor. Meanwhile, no one had been able to rest: the thought of little Markus in the killer’s hands made it impossible to catch even a moment’s sleep.

She read through Dante Kravina’s statement again, with her head in her hands and her back seizing up in pain.

“A lack of facial expressions,” she muttered, reviewing the description of the killer Lucia’s father had provided.

Marini approached her. “Are those his words?” he asked De Carli.

“More or less. Anyway, it was clear what he meant. He’d been pretty disturbed by it.”

“Lack of facial expressions, imitative behavior, and difficulties with language,” Marini summarized, reading through the report.

Teresa lifted her head up to look at him. He looked like he’d been gripped by a particularly interesting train of thought.

“Does that sound familiar?” she asked, not really expecting an answer in the affirmative.

He gave her a surprised look as if he were the first to doubt what he was about to say.

“The case of child number thirty-nine,” he said.

Teresa didn’t understand.

“Child number thirty-nine?” she repeated.

Marini sat down next to her and began typing something on the computer keyboard.

“I’ve been reading a psychology handbook,” he said. “There’s a lot of useless stuff in there, but this one really got to me because it’s just . . . so improbable. To think that it actually happened—it’s unbelievable. Here it is! Johann Albert Wallner,” he said, reading out a newspaper headline.

Teresa felt dizzy. Wallner, she thought. Like the name inscribed on the Hippocratic seal.

“Who is he?” she asked.

“A psychiatrist who was struck off for an illegal experiment he conducted almost forty years ago,” Marini replied. “Wallner,” he muttered, looking at the Nazi-era artifact they’d found. “His father was Wolfgang Wallner, a medical officer in the SS. The medal must have something to do with his profession.”

“Perhaps it’s a graduation gift,” Teresa suggested, counting the years in her head. She tried to remain calm and control her breathing, but it was proving difficult. How was it possible that she of all people—someone who had read everything there was to read when it came to psychology—had no recollection of this case? The article on the screen before her suggested that the case of child number 39 had made an enormous impact, enough to be included in the handbook Marini was reading.

Did I simply miss it, or has my mind already erased the memory?

“What experiment is this?” Knauss asked.