When Posy goes to stay at Pip`s house they have lots of fun together before bedtime. But just as they switch out the light, disaster strikes: Posy realises that she has forgotten her favourite frog toy. Desperate to help his distraught friend, Pip offers Posy a range of different toys to substitute for her frog, including his own favourite frog money box. But none of them will do, ”that`s the wrong frog!” Posy wails. It is only when Pip gives Posy his own, very favourite, pig toy that Posy is comforted and that the friends can get a good night`s sleep, at last.