I just finished Isabel Allende's Zorro. I enjoyed the book, but it wasn't what I expect. Perhaps "The making of Zorro" or "Zorro Part 1 - Birth to Return" would have been a better title. The book covers Zorro from birth, through his schooling in Spain and finishes with his return to California. You get to see how he got to be about 20. But that's where the book ends and the prologue doesn't leave too much room for a sequel.
In fairness, though it wasn't the story I was expecting, it was a good, straightforward read. Something you see less and less of these days. It's a good straightforward tale in the vein of Rafael Sabatini. (Captain Blood is still one of my favorites).
All in all, I'd recommend the book. Just adjust your expectations on what the story covers and it's worth it.