Isabelle Lightwood: Slept at Magnus' place?

Alec Lightwood: Didn't do much sleeping. I was helping treat Luke's wounds. That's all.

Isabelle Lightwood: Really?

Alec Lightwood: What?

Isabelle Lightwood: Nothing. I believe you.

Alec Lightwood: Okay, Magnus made cocktails. I'm telling you, nothing else happened.