One, Two, Buckle My Shoe is a nursery rhyme referenced in the novel with the same name. The rhyme: One, two, Buckle my shoe; Three, four, Knock at the door; Five, six, Pick up sticks; Seven, eight, Lay them straight: Nine, ten, A big fat hen; Eleven, twelve, Dig and delve; Thirteen, fourteen, Maids a-courting; Fifteen, sixteen, Maids in the kitchen; Seventeen, eighteen, Maids a-waiting Nineteen, twenty, My plate's empty. Agatha Christie's version of the rhyme has the variation "Eleven, twelve, men must delve".