"Someone Is Stealing the Great Throne Rooms of the Galaxy" is a short story by Harry Turtledove. It was published in August 2006 in Space Cadets, a hard cover published in conjunction with LACon IV, the 2006 Worldcon and edited by Mike Resnick. It was reprinted in Federations, John Joseph Adams, ed., published by Prime Books, 2009, and in Atlantis and Other Places, Roc, 2010. In Turtledove's entire career as a professional fiction writer, this is the only story for which he was ever offered a contract before he had written even a first draft.
The plot involves Space Patrol agent Rufus Q Shupilluliumash (a sentient alien hamster) and his investigation into the thefts of throne rooms from various planets in the Galactic Empire by a mysterious conspiracy.