Ooky feelings: this is it exactly. It's not so much that she loves her grandfather, or that she's willing to make off with the treasure. She's a thief, and a very selfish human being, and I can see it of her, and of Neal, who is able to ignore the moral ramifications of something unless it's shoved in his face. Her characterization in the season finale though typifies what's wrong with this whole arc. It's not the premise, it's the way none of the characters say, react to her telling them that her grandfather fought for Hitler in WWII. She had no hesitation in saying it. It's like it was just another conflict and they were just the guys on the other side. The way they write Alex in that episode makes it clearer than anything else that the writers just don't get it.