Why is everything on fire?

Party wakes up in a burning building, escapes the conflagration and encounters some villagers crying about the burned village. They locate the guy responsible, a nutjob firemage praying to a rat skull on a stick, and kill him. Once that's dealt with, they get on a boat back home. The boat is promptly shipwrecked, and the party finds themselves trapped on an island. In a cave on the island they find a pirate cove, and gamble with the pirate ghosts for their treasure. Victorious, they sail home on a skiff, fifteen thousand silver richer. 5000 Eeps.