I'll let you guess who our second protagonist is. Come on, don't be shy, I'll give you some hints: he's just the most conceited, cheekiest and wittiest djinn whose first-person narration I've had the pleasure of reading this past year.
In any case, this novel takes place far to the southeast and far before the events of Bartimaeus's Trilogy; in fact, it takes place before Bartimaeus even met Ptolemy. So that was a long time ago indeed.
As far as the prose goes, it's a bit more stately paced and not quite as crackling as the narration of the Trilogy went; but that actually really helps to remind the reader that the events took place a LONG time ago. Because old literature is always at a glacial pace and full of descriptions, you know? This novel at least doesn't take it to the same level as that, though, and it's a very fun read indeed.
Oh, and guys? I lifted the cover picture from this, which is a much better review of this book. It even uses a "something on/out of something else" rating system, which is slightly more straightforward than my system of "enjoyable, boring, annoying, okay, twist, unfinished and wtf", no?