From the idea of the plaster cast in the first place, to the 'whoever loses tries it first' to the pure hotness of Draco teasing Harry, to the thing going wrong. Incendiary, indeed :). And I laughed out loud at the 'perverse rituals' ;). Phew! at the end too - so glad little Harry survived despite the dose of plaster dust.
And that's one title where it's impossible *not* to have a look at the fic afterwards - brilliant! :)