Lonely after their family moves to London, Ben and Hattie are delighted to find a new friend in the park: a talking lion wearing a top hat, dress suit and red cravat. But not only is Mr Dandy Paws an exceptionally well-dressed feline, he's a highway lion who robs from those who are cruel to animals and invests the proceeds in animal justice. But with a P.I. on his tail, Dandy's latest scheme – a daring break-out at London Zoo – could get Ben and Hattie into far more trouble than they bargained for ...