Blind since her mother's sudden death when she was a child, Emma of Gistel thinks she'll spend the rest of her days running the castle with her uncle, until her father's surprise return from crusade launches her on a journey from Flanders to Santiago de Compostela in Spain. Her father left twenty years before to expiate the crime of his wife's murder, but now he has returned with a pregnant young bride in tow, and threatens to send Emma to live in the convent where her mother is remembered as a saint. But a chance rescue in a tavern brawl of Katherine, the young sister of the count of Flanders, offers her a new opportunity.
(your hook starts here) What begins as an ordinary mission to escort her young charge, Katherine, to her prospective bridegroom, the son of the queen of Castile, turns dangerous when Katherine is captured by the queen's rival, the king of Aragon. Assisted by her traveling companions, Aimery and Oliver, two clerics with a plan to write a guidebook for the pilgrimage road to Compostela, and Yusuf ibn Cid, a mysterious messenger with an unknown agenda and ambiguous allegiances, Emma tries to rescue the girl. When their efforts end in tragedy, Emma completes her journey to Compostela and forges a new life for herself in Spain.
And there's a great dog on page one. (Killer Yapp says: finally someone who understands what a GREAT hook is--a dog)
This is a synopsis, not a hook. Start with Emma. What's her biggest problem? Leave out all these other characters except the antagonist.
You mention she's blind, but it never gets mentioned again. Does it factor into the story? Descriptives like blind, gay, dyslexic, and/or nouns like winged horses are like Chekhov's gun: mention it in the first paragraph and you'd better use it by the end of the show.