Forceful Swedish Police Procedural from Johana Gustawsson, BLOOD SONG

Between the harsh cover design and the threatening title, readers eyeing the American release of Johana Gustawsson's "Roy & Castells Thriller" BLOOD SONG (Orenda Books) could figure the book for gory, gruesome, and dark. And some readers might not open it, as a result.

But although this detailed police procedural investigates a multiple murder that's  part of a series of killings rooted in historical horrors from Spain's Franco years, the focus of Gustawsson's writing, as in her award-winning Block 46 and Keeper, is on the tender and insight-laden interactions of two detection professionals: profiler Emily Roy, and crime historian Alexis Castells. Each woman walks with significant wounds from her courageous interludes in the past, but they've worked together before and built significant trust. So when the arc of investigation begins to curve toward their own families, each can borrow strength from the other and keep moving forward.

Gustawsson interleaves three, even sometimes four, points of view, clearly marked at the start of each chapter with place and date -- so this diverges from a traditional narrative. The most baffling flashbacks, horrible in the abuse and torment portrayed, are set in Spain in the 1930s. Only knowing that this skillful storyteller must have a purpose can pull them into the mystery at hand. At it's not until well past the midpoint of the book that the strands show their deeper connections.

Instead, the action begins with a triple murder in Falkenberg, Sweden, in December 2016, not long before the long-planned wedding for Alexis. Although Emily is based in London, she's immediately drawn into the case because the victims are family members of a younger woman she cares very much for, named Aliénor. Emily's own inner traumas are massive -- they're not explained fully here (see at least Keeper, before or after you read BLOOD SONG, or just go with the flow, as Emily's colleagues do), but her unemotional presence in crime-solving team meetings says a lot, as does her coping mechanism while investigating such horrors:

The cold struck her full in the face as Emily stepped outside the station. Greedily sucking in a few breaths of icy air, she crossed the street and went to sit on a low stone wall beside the pavement. Then she took a little black box out of her inside coat pocket. She opened it and gazed inside for a few seconds.

That was always the hardest part. Being in tune with her senses, without letting her emotions overwhelm her.

Emily tucked away the image of Aliénor in the empty box. She contemplated her friend's face for a moment, then closed the lid.

Gustawsson's writing, and her clear insistence that injustice must be exhumed and confronted, make it necessary to press forward with Emily and Alexis as the meaning of the crime finally emerges — along with other disturbing secrets. Some crimes take a generation or more to solve. But in this book, as Martin Luther King Jr. asserted, "the arc of the moral universe is long, but it bends toward justice."

PS:  Looking for more mystery reviews, from cozy to very dark? Browse the Kingdom Books mysteries review blog here.