This time, it's Caius that's in trouble (read the book to find out just how and why). It all started when the boys decided to buy their teacher a birthday present, and got him (they think) a deaf and dumb slave named Udo. That's just the start of their troubles, because Udo is more than he seems, and they suddenly find themselves in a web of intrigue and murder, when they stumble on a plot to assassinate a famous senator. It could be one of their fathers!
In this novel, we learn more about the boys, as they display their loyalty and courage. Caius, for one, isn't the same brawny wannabe Hercules he was in the last one, but shows his brave side.
It all takes the same wit, hair breath'd escapes, razor-sharp logic and good sense and you have yourself another wonderful novel!