When the Countess of Morcar's priceless blue carbuncle is stolen, a reformed thief is charged with the crime. But a strange thing happens. Trivial is what Sherlock Holmes calls it. He's studying an old hat when Dr. Watson visits to wish him "The compliments of the season." Holmes tells Watson about Commissionaire Peterson's report of seeing a little knot of roughs assault a man carrying a Christmas goose home for the family. They all ran, leaving both the goose and the hat. No one could locate the man, Henry Baker, whose name was tagged to the goose so Peterson took possession. Soon another strange thing - Mrs. Peterson found Morcar's fabulous blue jewel inside the goose while preparing it for their family festivities. Can S.H. sort this all out?