"You're just a piece of cheese."

The Death of Rats must be imaginary, decides Susan Sto Helit. Tiny rat skeletons wearing robes and carrying tiny scythes do not exist. She must be imagining this one because of the cheese on toast she had at supper the night before. Thus begins the acquaintance of Susan, duchess of Sto Helit (it's complicated) and adopted granddaughter of the Death of the Discworld, and the Death of Rats, a tiny piece of Death which the Grim Reaper allowed to maintain an independent existence when he was "reconstituted." (Even more complicated-- there's a whole book about it.) 

This week we begin to come to know both Susan and the little skeletal rat she initially insists must be imaginary. We find out about Susan's personality, and about the steps her parents took to stop her remembering about being Death's granddaughter, including giving her an education. To paraphrase Sir Terry, though, "Education is easy. Learning things is harder."