 between the pipe and the roof itself. And then there's flashing that goes around that. That's the most common place for a roof leak when you have it leak right above a bathroom. And a lot of times contractors will try to sort of tar that in place, but that's a bad idea. What I would recommend is to take out the plumbing vent flashing. And you can do that easily by removing a few shingles in that area. Roof shingles are actually pretty easy to disassemble if you know kind of a trick of the trade. I like to do it with a flat bar.