Apollodorus is a merchant at Philadelphia in the Decapolis of ancient Palestine. Since the beginning of the Jewish War, his excursions have been more perilous and on his most recent return trip, he has brought back a man left to die by the Romans--a man who has no memory of what happened to him or even his own name. "Xenos", as he is called, is befriended by Apollodorus's young son, Philo--one of three, the others being Conan and Nicanor.
On his next caravan, however, Apollodorus is killed and his sons are forced by financial concerns to lease their property to the Roman garrison. Conan decides to join the Roman federated troops to earn his living while Nicanor steals off to join the Jewish resistance. Philo remains at home to serve the Roman garrison and care for Xenos, who soon recalls his past--a past which goes back to the previous book in this series, The Ides of April. Events will bring the three brothers back together as each tries to make sense of the war and the suffering of the Jewish people.
In terms of historical research, Beyond the Desert Gate recreates life in Roman Palestine very well. My major gripes with the book are the ponderous plot and insufficient character development. The book is the fourth part of a series of five books and has trouble standing on its own. The description of the siege of Macherus was well done, particularly the climax which was very affecting, and the Christian elements were also appreciated. But over all, I think this book will have trouble holding the attention of the audience it's intended for--older kids ages 14 and up.