The monarchy is not what it used to be. King Victor II may be the grandson of Queen Victoria, but political and economic realities have intruded even on Buckingham Palace, where family breakfasts center on proposals for tightening the household budget and the King, a licensed physician, fumes at Parliament's refusal to permit him to practice medicine for fear of lawsuits. Nor has royal dignity been spared. A practical joker has invaded the palace, but his tricks, initially amusing, have turned deadly, and seem increasingly to be focused on the teenage Princess Louise. The trickster, it seems clear, wants her to divulge some secret to the Greater British Public, but which one?