Esca, on the other hand, is that figment of the Imperial imagination- the noble savage-cum-devoted side-kick. (Think Man Friday, think Tonto.) I can't believe in him at all unless, of course, he's head over heels in love with Marcus- but that's not something Sutcliff- writing for kids in the 50s- is in a position to explore. If he's not in love with Marcus then he's just a quisling- a house negro.
This is a story of imperial adventure. The natives are colourful but the Romans are sahibs. It's very well done, but I'm fresh from reading Kim which covers the same ground with very much greater subtlety and penetration...