What is the theme in The Slippery Slope by Lemony Snicket?

Fire is a recurring part of "The Slippery Slope." The Baudelaire children lost their home and their parents to fire, and Count Olaf and the others in his organization enjoy burning things down. Fire also seems to have something to do with the VFD, the secret organization that the Baudelaire's parents seem to have belonged to, and from which Olaf and others split. According to Quigley Quagmire, VFD may stand for Volunteer Fire Department, organizations that fight fires.