The Fire Thief by Terry Deary

Main Characters: Prometheus, the Titan; young Jim, an orphan
Location: Ancient Greece, and a city which resembles Dickensian London
Time period: Ancient Greece, and the 1850s
Genre: J Fiction, Fantasy, Greek mythology

The Fire Thief is an odd book which combines Greek mythology with the London of Charles Dickens. (Only it isn't called London in the book--it's Eden City.)

You probably know the story of the Titan Prometheus who stole fire from the gods to give to humans and was then punished by being chained to a rock and having an eagle eat out his liver every day. One day Prometheus kills the eagle and escapes. (Though in the actual myth he is rescued by Hercules.) His cousin, Zeus, who holds a certain sympathy for him even while believing that he must be punished, gives him a chance to be forever free. Prometheus is allowed to go down and live among me and search for a hero. If he can prove to Zeus that humans have the capacity for heroism, then he will be forgiven. Zeus even gives Prometheus his swan wings so that he can fly to any time period. Of course, until he fulfills his quest, the eagle (who isn't a real eagle but the avenging Fury and who isn't really dead) will continue to hunt for him.

Prometheus travels to the future (well, the past from our perspective) and encounters young Jim, an orphan in the employ of a con man. Jim is actually the narrator of the story, and employs a lot of footnotes to explain himself as he goes along. These can be either clever examples of meta-fiction, or really annoying. (If you're annoyed by all these parenthetical interruptions, you'll probably be annoyed by the footnotes.)

If the footnotes don't bother you and you enjoy this book, look for its sequels Flight of the Fire Thief and The Fire Thief Fights Back.