Alfie has always loved playing in the overgrown garden next door. It is here he plays with Penguin, an enormous black- and-white cat, a stray who Alfie has claimed as his own. But when his next door neighbour's granddaughter, Grace, comes to live with her, she decides Penguin belongs to her! Alfie knows he can't force Penguin to be with him, but he wishes the cat didn't want to spend time with Grace either. What neither of them realises is that while they thought Penguin was with the other one, he has actually disappeared…