*Many thank to Graham Brack, Sapere Books and NetGalley for arc in exchange for my honest review.*
Three things prompted me to request this novel: the fact that it is a historical fiction set in the 17th century Netherlands and the author, whose series with Josef Slansky I found quite enjoyable. 
Master Mercurius, a protestant minister and a scholar at Leiden University, is asked to travel to Delft and assist the local men of importance to solve a mystery of the abduction of three young girls, one of whom was found dead. Mercurius is helped, among others, by Master Vermeer, who, in fact, finds the clue to the mystery.
Mercurius is a likeable character, intelligent, witty, with a common sense and some distance towards himself. And he has a secret. He converted to Catholicism in France, and became an ordained priest. His Protestant status allows him to be accepted in the society and to pursue his academic career. The descriptions of the places, the clothes, the architecture, the customs and the interiors are superb, and you do get the feel of the times. 
There are some hints in the novel that it is the first one of a new series, which sounds promising to the fans of HF.

I chose to read this new historical mystery series from Graham Brack because I adore his Prague set Josef Slonsky series. This takes a rather different path, we are in 19th century Netherlands, a Protestant country, where the Catholic ordained priest, Master Mercurius, has bowed to current circumstances and has additionally been ordained as a minister too, his heart though lies with the Catholic faith. It his latter ordination that allows him to be employed as a gifted cleric at Leiden University. It is 1871, amidst a bitterly cold winter, the Rector has asked Mercurius to travel to the small town of Delft at the request of their mayor.

Delft is in a state of fear and anger, three young girls, aged between 8 and 9 years old, have been abducted, and one, Gertryd, has been discovered dead with a cross on her face in a frozen shallow grave. It is Mercurius's task to find the murderer, and hopefully discover the remaining girls, Magdalena and Anna, alive. There are worries that other girls are at risk of being taken too, and it is a matter of urgency that Mercurius gets to the truth as soon as possible. He works with a group of leading men in Delft, including the rational and logical Van Leeuwenhoek, and to my great delight, the artist, Johannes Vermeer, whose artistic talent has been deployed to draw a picture of the dead girl in her grave. Vermeer is a bright, benevolent, happily married man with 9 children, who loved his wife so much that he was willing to convert to Catholicism. Trying to find a connection between the taken girls proves to a difficult task, they come from different backgrounds, Magdalena was born out of wedlock, she and her mother are shunned by the community, and the sheltered Anna comes from a privileged and wealthy family.

It is Vermeer who eventually hones on the crucial factor that connects the girls and this allows Mercurius to get closer to the tragic truth of what lies behind the abductions, aided by a strange comment made by Anna's mother that she knew that this would happen one day. Brack creates a vibrant picture of the period in Delft with his rich descriptions, the poverty, the position of women and girls, the prostitution, the effects on a person of being a Catholic in a Protestant nation, and the attitudes of the time. Mercurius in a compassionate and merciful man, doing what he needs to survive, having to keep his Catholic faith secret, a man of his time. This is a great start to this new historical series, although I am not certain that I will be pursuing it further, I am just a greater fan of the Slonsky series and hope that Brack will continue that. Many thanks to Sapere Books for an ARC.