Excerpt from The Invisible Guardian by Dolores Redondo, plus links to reviews, author biography & more

"She smells of tobacco. Do you know whether she was carrying a bag?"

"Yes, she was. It hasn't turned up yet, but I've got officers combing the area as far as a kilometer downstream," said Inspector Montes, gesturing toward the river with his arm.

"Ask her friends where they were and who they were with."

"I'll do it first thing in the morning, chief," said Jonan, tapping his watch. "Her friends will be thirteen-year-old girls, they'll be asleep right now."

Amaia observed the girl's hands lying beside her body. They looked white and unblemished, and their palms were turned upward.

"Did you notice how her hands are positioned? They've been arranged like that."

"I agree," said Montes, who was still standing next to Jonan.

"Get them to photograph and preserve them as soon as possible. She may have tried to defend herself. Her nails and hands look fairly clean, but we might be in luck," she said, addressing the officer from forensics. Dr. San Martín bent over the girl again, opposite Amaia.

"We'll have to wait for the autopsy, but I'd suggest asphyxiation as the cause of death, and given the force with which the string's cut into her skin, I'd say it was very quick. The cuts on the body are superficial and were only intended to slash her clothes. They were made with a very sharp object, a knife, a cutter, or a scalpel. I'll confirm this for you later, but the girl was already dead by this point. There's barely any blood—"

"And what about her pubic area?" interrupted Montes.

"I think the killer used the same blade to shave off her pubic hair."

"Perhaps he wanted to take some away as a trophy, chief," suggested Jonan.

"No, I don't think so. Look at how it's been scattered at the sides of the body," observed Amaia, pointing out several small piles of fine hair. "It seems more likely he wanted to get rid of it to replace it with this." She gestured to a small, sticky golden cake that had been placed on the girl's hairless pubic mound.

"What a bastard. Why does someone do that sort of thing? As if it wasn't enough to kill a young girl without putting that there. What on earth could he have been thinking to do something like this?" exclaimed Jonan in disgust.

"Well, kid, it's your job to work out what that swine was thinking," said Montes, going over to San Martín.

"Was she raped?"

"I don't believe so, although I won't know for certain until I examine her more thoroughly. The staging is decidedly sexual . . . cutting her clothes, leaving her chest exposed to the air, shaving her pubic area . . . and, of course, the cake . . . It looks like some kind of cupcake, or—"

"It's a txantxigorri," Amaia interrupted him. "It's a local speciality made with a traditional recipe, although this one's smaller than normal. It's definitely a txantxigorri, though. Jonan, get them to bag it, and please," said Amaia, addressing the group, "don't mention this to anybody. It's classified information, at least for now."

They all nodded.

"We're finished here. She's all yours, San Martín. We'll see you at the institute."

Amaia got up and took one last look at the girl before climbing up the slope to her car.

Excerpted from The Invisible Guardian by Dolores Redondo. Copyright © 2016 by Dolores Redondo. Excerpted by permission of Atria Books. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.