Building a spellthief.

I've been kicking around the idea of building a character based off of the spellthief class in That Other Game. For those of you that don't know, the idea is a stealthy character that steals the spells from her enemies minds to cast herself. After some thought, I'm not exactly sure how to model this. So, as my DM's usual answer is, "Go ask the Forums.", I come to you, the experts, for advice.



Thanks.

Building a spellthief.