From the publisher's description: (super inaccurate)
Mags, Herald Spy of Valdemar, and his wife, Amily, the King’s Own Herald, are happily married with three kids. The oldest, Peregrine, has the Gift of Animal Mindspeech—he can talk to animals and persuade them to act as he wishes. Perry's dream is to follow in his father's footsteps as a Herald Spy, but he has yet to be Chosen by a Companion.
Mags is more than happy to teach Perry all he knows. He regularly trains his children, including Perry, with tests and exercises, preparing them for the complicated and dangerous lives they will likely lead. Perry has already held positions in the Royal Palace as a runner and in the kitchen, useful places where he can learn to listen and collect information.
But there is growing rural unrest in a community on the border of Valdemar. A report filled with tales of strange disappearances and missing peddlers is sent to Haven by a Herald from the Pelagirs. To let Perry experience life away from home and out in the world, Mags proposes that his son accompany him on an expedition to discover what is really going on.
During their travels, Perry’s Animal Mindspeech allows him to communicate with the local wildlife of the Pelagirs, whose connection to the land aids in their investigation. But the details he gleans from the creatures only deepen the mystery. As Perry, Mags, and their animal companions draw closer to the heart of the danger, they must discover the truth behind the disappearances at the border—before those disappearances turn deadly.
Summary taken from reading the ACTUAL BOOK:
Mags' eldest son is Perry (Peregrine). Mags and Perry head off on a training mission, posing as a single caravan of traders: father and son, headed off based on a report of missing people from an old Herald who has some trouble with reading and writing. Once arrived, Perry is Chosen by a kyree, and he and Mags and their Companions head off into the wilderness to try and figure out what's causing the disappearances of a series of people. The Hawkbrothers are long gone from the area, but they left behind Crow bondbirds and a herd of sentient Elk, who each, after an assist from impulsive and goodhearted Perry, agree to assist in the spycraft training mission. Unfortunately, the true cause of the disappearances is a greater threat than the spy duo ever imagined it could be, and after an unfortunate incident at a "honeytrap" of an inn, Mags is left to try and coordinate between the remote borderlands and Haven while Perry sets off on his own into hostile territory, trying to fly under the radar of a rogue (and crazed) Mindreader who has been assembling an army on the border of Valdemar. To complicate matters, the Mindreader has settled in what has to be the most peculiar city ever imagined, and there's a hostile mind there too.