Adam: Um, did you happen to, uh, use marquis reagent in your kit last night?
Adam: Uh, it's what caused the burn in the vic's clothing.
Mac: And you think I might've what, sprinkled some around the crime scene?
Adam: (Chuckles) N... no... no, I have no... I mean... I mean, what I'm trying to...
Jo: You have to admit he has a point. What other explanation would there be?
Mac: Find one.