In this, Paddington the bear, settled in with the Brown family, is a popular member of the community who spreads joy and marmalade wherever he goes. One fine day, he spots a pop-up book in an antique shop -- the perfect present for his beloved aunt's 100th birthday. When a thief steals the prized book, Paddington embarks on an epic quest to unmask the culprit before Aunt Lucy's big celebration.