Have you ever had so much fun reading a book that you actually talked to it?

Not the book itself (although that's what it looks like to anyone who sees you), but the characters in it and sometimes even the author him- or herself' There's no surer sign that I'm enjoying a book than my refusal to care that I look like a crazy person.

If that level of fun is what you're looking for, take a look at Nick Harkaway's Angelmaker. I won't even attempt a summary. It's impossible and whatever I come up with couldn't possibly show you the sheer mad fun of it all.

So let's start with characters.

Joshua Joseph Spork is the shambling heart of the book. Joe is a nice guy, so intent on doing the right thing and not bothering anybody that he is incapable of figuring out when a girl is flirting with him. Although he has broken with his father's underworld life, he keeps their secrets and remains polite to any of his father's former colleagues he runs into.

Joe's bumbling, Everyman decency is heartening, amusing, and very, very necessary, because there are shadowy forces out there determined to break him, and they do a mighty fine job of it. Our outrage on Joe's behalf keeps this cockamamie story grounded.

Joe is not the only character you'll fall for. Harkaway's cast is quirky and memorable and outrageous. From Joe's felonious pal Billy Friend to mad former monk Ted Sholt to the seemingly immortal evil of Shem Shem Tsien, each character will make an impact on you.

And then there's the women! I swear, I fell in love with every single woman in the book: old Edie, young Edie, Dotty Catty, Cecelia Foalbury, Frankie, Polly Cradle. All of 'em. They're brash and strong and loyal and excellent foils to Joe's placidity.

It's a big, solid book full of crooks and con men, impossibly complicated clockwork devices, a malodorous pug with one tooth and a bad attitude, saucy lady spies, French mathematicians, mad monks, governmental cover-ups, dotty old ladies, serial killers, an Undertaker's Guild, nuns, lawyers, oriental despots, and, at its center, a huge man dedicated to delicate clockworks just trying to do the right thing and honor his grandfather, an unyielding man with a gift for delicate work and a broken heart that never healed, and not become his father, a notorious criminal and lordly Prince of the London underworld.

And if all that isn't enough to convince you to give this a try, then you don't know what you're missing.