It seems that Scandinavian mystery novels have not been appearing quite as quickly in the United States as they once did, which makes us appreciate all the more the ones that do show up. Thus we herald the appearance of Katrine Engberg’s THE BUTTERFLY HOUSE, which is ably translated by Tara Chase.

Engberg introduced Copenhagen police detectives Jeppe Kørner and Anette Werner in 2020’s THE TENANT. Both return in THE BUTTERFLY HOUSE, though their partnership is somewhat tenuous. Anette is on maternity leave for the entirety of the book, which leaves her out of sorts on several different fronts. Jeppe is recovering from a painful divorce and is living with his mother while waiting to move in to a new apartment. He also is tentatively taking some giant steps into becoming emotionally involved with another member of the detective squad.

"There truly is no logical way of discerning whodunit prior to the big reveal that occurs near the end, after which a number of the subplots that have developed along the way are satisfactorily wrapped up."

A puzzling case is dropped into the midst of this cauldron. Someone is committing a series of murders around Copenhagen, draining the blood from individuals and leaving them on successive nights in a body of water. Each victim is connected to The Butterfly House, a private treatment facility for troubled teens that closed after being in operation for only a couple of years, and Werner realizes that she knows one of these poor souls. Jeppe and his team don’t lack for suspects once they start investigating people with ties to the facility. Their problem is that each possible suspect is also a potential victim. Given the high public profile of the killings, Jeppe is under the gun to either resolve the investigation quickly or be replaced as the head of the team.

Meanwhile, Anette remains uncomfortable with the inaction that comes from being on maternity leave and is not exactly embracing the role of parenthood. She begins taking a few hours here and there to do her own investigating, which she does very well, even as she puts her relationship with her husband --- not to mention her own life --- in jeopardy. The matter is ultimately resolved, though not without some difficulty, and a surprise or two that will keep readers going until they finish just one more chapter, followed by another.

The most impressive element of the book is the mystery that forms its red-hot core. There truly is no logical way of discerning whodunit prior to the big reveal that occurs near the end, after which a number of the subplots that have developed along the way are satisfactorily wrapped up. Hopefully we will see BLOOD MOON, which precedes THE BUTTERFLY HOUSE in the series, to get more of the same. In the meantime, it is my fervent wish that Katrine Engberg continues to write and never stops.