Basically, Grant Morrison hid balloons filled with his drugs up his rear end during a cross Atlantic flight. They popped on the flight, and he started tripping the **** out. He was really paranoid and felt like he had to fart the most destructive farts in the history of mankind, and would be unable to do so discreetly, but couldn't get up to go walk to the bathroom because he was completely hosed up. So he eventually couldn't take it anymore and he just lets it go, but apparently no one noticed, so he felt pretty good about himself.
Eventually his trip passes, the plane lands, and he walks off. He kind of struts through the airport sporting a really crisp, white suit thinking he's the cat's loving meow. He gets in a cab and heads to his hotel, where upon unpacking he sees himself in a full length mirror.
****.
All over the back of his pants and suit jacket.
He was so out of his mind on the smuggled drugs he failed to notice that he shat himself on that plane ride, and he had been walking around with a giant brown mess all over his nice white suit.