Is anyone familiar enough with this module to know when the PCs are supposed to hit level 12 and 13? It says the PCs should start at level 11 and reach 13 by the end of it, but it doesn't say when they should gain the levels. Calculating up the XP doesn't seem to work out right either. My players are about a third of the way through the module and are only about half way to level 12 XP wise.