
Two days after Christmas, Watson visits Sherlock Holmes and finds him examining a battered old hat. The hat and a Christmas goose were left behind after a disturbance in a London street. Holmes begins reconstructing the unknown owner's life from the smallest marks, and the seemingly harmless holiday puzzle soon takes an unexpected turn.

On the morning after the Christmas holiday, Watson finds Holmes studying an old hat that Peterson picked up after a street scuffle. Its owner is unknown, but the size, wear, dust, stains, and lining give Holmes a surprising portrait of the man who once wore it.

Just as the matter of the hat seems settled, Peterson the commissionaire rushes in, looking alarmed and bringing unexpected news about the goose he found. Holmes immediately grasps the importance of the development and decides to place a newspaper advertisement to find the owner of both the hat and the goose.

Henry Baker answers the advertisement and explains where he obtained the goose. Holmes and Watson step into the freezing London night, following the chain from a Bloomsbury inn to Covent Garden Market. There, a reluctant poultry dealer must somehow be persuaded to identify his supplier.

At the market, a frightened little man is urgently asking about the same geese. Holmes follows him and offers to help with his search. The stranger accompanies Holmes and Watson back to Baker Street, where Holmes questions him before the fire about the bird he is trying to find.