"Mabel Beaumont's husband Arthur loved lists. He'd leave them for her everywhere. 'Remember: eggs, butter, sugar'. 'I love you: today, tomorrow, always'. But now Arthur is gone. He died: softly, gently, not making a fuss. But he's still left her a list. This one has just one item on it though: 'Find D'. Mabel feels sure she knows what it means. She must track down her best friend Dot, who she hasn't seen since the fateful day she left more than sixty...

"Penny has never met anyone smarter than her. That's par for the course when you're a savant--one of less than one hundred in the world. But despite her photographic memory and super-powered intellect, there's one question Penny doesn't know the answer to: where did her father go when he left her and her mother years ago? On Penny's 21st birthday, she receives a card in the mail from her father, just as she has every year since he left. But this birthday...