I'm kinda excited about this drama too. It's kinda like Andrew and Janie's lakorn: Taung Paun Kamathep.
He kidnaps her because he thinks he played with this dead brother's heart, but actually it's her sister or cousin or something. If I'm reading everyone's comment correctly.
Well they like to reuse this concept a lot in thai dramas.
In Taung Paun Kamathep, Andrew kidnaps Janie because he thinks that janie is gonna marry to his dad but actually janie's sister is the one marrying andrew's dad. Andrew takes her to an island. They have this capturer and captive relationship and when they go back to bangkok, he finds out who she really is. They somehow get married because you know he has to take responsibility for the "things" that happen in the island. Jealousy, blah, blah, she some how becomes his secretary and they live happily ever after.
I think this new drama is gonna be a variation of Taung Paun Kamathep.