The Chicago Rules

What advice did Benton Fraser give his daughter when she went to Chicago?

This work appears in my post-canon serialized Due South novel, Northern Lights, as a letter of advice that Benton Fraser writes to his daughter Elizabeth before she travels to Chicago on the trail of her best friend's killers. I am posting it as a stand-alone work for fans who may be interested but don't want to read an entire novel. Can you guess where some of this advice comes from?

For the context of this letter, see chapters 6 and 10 of Northern Lights.