William Ryan’s historical mysteries featuring Captain Korolev, a Moscow Militia police investigator, are becoming another ‘must read’ for me. The books are packed with a wealth of period detail; set in the mid years of Stalin’s rule, the Terror is beginning to be felt collectively around the city and everyone fears the knock on the door in the middle of the night. There’s always a good mystery at the heart of Ryan’s books and The Twelfth Department is no exception.

Korolev is on holiday and intends to spend time with his young son Yuri, who has made the trip to Moscow by train. However, on the first day of Korolev’s leave he is asked to visit the apartment of an eminent scientist who has been shot dead. To his dismay, Korolev discovers that the ambitious and disliked scientist was undertaking research which is being monitored by those in power. He is taken off the case and travels with Yuri to the countryside, but during the trip his son disappears. After the death of another scientist, Korolev is seconded to State Security to investigate the killing and becomes embroiled in the political machinations between warring NKVD departments.

It’s usually around the third book in a series that familiar characters take on more substance and this is certainly the case with The Twelfth Department. Both Korolev and his sergeant, Slivka, have an interesting relationship, admiring each other’s capabilities but constricted by the roles in an increasingly paranoid department. The relationship between Korolev and Valentina, the woman he shares his apartment with, is also developed more and displays a softer side to the Captain. It also suggests an interesting sub-plot for the next book.

The Terror element isn’t overdone: it’s ever-present and pervades everyone’s decisions but the crime/mystery element is given space to flourish. Ryan always presents a solid police investigation and here, there are plenty of twists and turns until we reach the conclusion. The evocation of thirties Russia is excellent and even minor scenes, such as the description of the Moscow zoo and the delight that children take in watching the animals, bring the era to life.

Overall I think that this is the best book yet in a series that is going from strength to strength. The book isn’t published until the 23rd May but I was lucky enough to be sent a copy by Mantle, the publisher. And naturally I couldn’t resist reading it.