Take one obscure Grimm fairy tale ("Maid Maleen"), set it in ancient Mongolia, and you have Shannon Hale's Book of a Thousand Days in a nutshell.

Of course, it's a lot more than that.

It's a fantasy more concerned with characters than magic, an ambitious retelling that stands as a story in its own right, a glimpse into an unfamiliar world alive with history and culture. It's a subtle coming-of-age story. And though I enjoyed The Goose Girl, it's my new favorite book by Shannon Hale.

Book of a Thousand Days takes the form of a journal kept by 15-year-old Dashti, maidservant to Lady Saren. As the book opens, the two are being bricked into a tower for the next seven years because Saren has refused to marry the suitor of her father's choice, the terrifying Lord Khasar.

Astute readers will already have noticed that seven years add up to considerably more than a thousand days (2,555, not including leap years), so I'll offer a minor spoiler: the girls escape, though not before dealing with boredom, rats, dwindling supplies and a visit from Saren's rejected suitor.

As it turns out, leaving the tower is only the beginning. Disguised as scullery maids, Saren and Dashti find their lives outside complicated by courtly intrigue, dangerous secrets and old enemies -- and a few old friends as well. Even before Lord Khasar makes an unwelcome reappearance, Dashti struggles to reconcile her conflicted loyalties to Saren and the people she loves. But through her own cleverness and courage, one very unusual servant girl may just be able to save her mistress, her realm and herself.

The fantasy Mongolian setting is vividly rendered, but what really distinguishes Book of a Thousand Days is the strength of Dashti's voice. Practical, resilient, a little naive and unflinchingly honest, Dashti is a compelling narrator whether she is detailing her ambivalent feelings toward the fragile, childish Saren, reminiscing about her mother and life on the steppes or cooing over a handsome yak.

Because there is never any question that this is in every sense Dashti's book, other characters are a bit less well developed, and the more action-driven part of the plot involving Lord Khasar is glossed over in favor of Dashti's personal and romantic tribulations. It's a good thing she's so likable.

Hale's supple prose is graceful but not flowery, and the many ink sketches throughout Dashti's journal help bring her world to life, yaks and all. Teen and tween readers who enjoyed the first-person narrators of books like Robin McKinley's Beauty and Tanith Lee's Wolf Tower should snap this one up.