Series: Marcus Didius Falco #4
Falco is sent by Titus Caesar to Moguntiacum in Roman Germany to deliver an iron hand (it's a sculpture) to the Fourteenth as a sign of the emperor's favour. He's also tasked with finding Munius Lupercus who was captured and sent to the witch priestess Veleda and finding the rebel leader Julius Civilis. Veleda apparently lives in the forest in Germania Libera, so he'll be behind enemy lines, so to speak, as well.
I had a lot of fun with this one. It's basically a Roman gumshoe story through the wilds of untamed German forests although it starts out as gathering background information in Moguntiacum and its surroundings. It takes a while for the forest to feature in the story but there were some rather creepy scenes in the Teutoberg forest where Falco and his companions stumble across an abandoned Roman camp and find themselves in the middle of a sacred grove complete with human bones. A couple murders are even solved although they don't feature as a central focus of the story. I really liked Helena Justina's brother Quintus Camillus Justinus in this too. And his dog (an excitable puppy who gets taken along with them through the forest).
I read this for the "In the dark, dark woods" square of the Halloween Bingo. I've decided that it fits because of the travel through the Teutoberg forest to find Veleda and for the creepy scenes mentioned above. There's also forest around Moguntiacum although it doesn't feature in the actual plot so much. The book could also fit the "Terrifying Women" square and maybe the "Amateur Sleuth" square although as an informer Falso is basically a private detective hired by the emperor (or his son, technically).