Paddington Bear, having settled with the Brown family in Windsor Gardens, has become popular in his community, offering people emotional support in various ways. To purchase a unique pop-up book of London in Samuel Gruber's antique shop for his aunt Lucy's 100th birthday, Paddington performs several odd jobs and saves his wages, but the book is stolen. Paddington gives chase, but the culprit escapes, and Paddington is framed and arrested. Although Mr. Gruber and the Browns do not believe that Paddington stole the book, with no evidence that the thief even existed, Paddington is wrongfully convicted and jailed. The thief soon returns home and is revealed to be Phoenix Buchanan, an egotistical actor who lives opposite the Browns.