Ottoline is back in a brand new adventure! Ottoline and Mr. Munroe love puzzles, clues, and mysteries. One day, they meet an enigmatic purple fox, who offers to take them on a night-time urban safari. The fox shows them all the hidden animals of the city and Ottoline makes notes on them in her field notebook. Mr. Munroe is making notes, too—on the anonymous poems he finds stuck to lamp posts on their journey. Who is the secretive poet, and how can he and Ottoline help them mend their broken heart? Includes a fold-up-and-keep fortune teller!