Madison Spencer, the liveliest, snarkiest dead girl in the universe, continues the afterlife adventures she began in Damned.      Having somewhat reluctantly escaped from Hell, she now wanders the Purgatory that is Earth as a ghostly spirit, seeking her do-gooding celebrity parents, fighting the malign control of Satan, recounting the disgracefully funny (to us, anyway) encounter with her grandfather in a fetid highway rest stop in Upstate New York when she . . . oh, never mi