Misleading descriptions

Inspired by a Scalzi article on accurate but misleading movie descriptions, I tried some of my own. Not always as complete as his:

Cordelia's Honor: a woman falls in love with her captor and is convinced to cover up a mass murder.

The Warriors Apprentice: a mentally unstable noble acquires a private fleet through deceit.

Nine Princes in Amber: the inmate of an insane asylum has increasingly surreal adventures.

The X-Men: a teen runaway meets and falls for a much older and dangerous man.

Castle in the Sky: two kids defy the advice of their elders and destroy a priceless historical site.

Nanoha: a boy spends months living with a girl without telling her he's a boy.

Lord of the Rings: a special forces team sets out to infiltrate enemy territory and assassinate the enemy leader. Multiple betrayals ensue.