In certain respects, the tale of the Ka-Nefer-Nefer follows a familiar script: like many disputed antiquities, the Egyptian funerary mask was unearthed last century and quickly vanished, spending nearly 50 years in obscurity before resurfacing on the European art market in the late 1990s. The St. Louis Art Museum soon bought the mask -- an elaborately tooled cartonnage of blended gold, glass and linen. It has since become the centerpiece in a bitter ownership dispute between the museum, which claims clear title, and Egypt, which charges the mask was plundered from a government storeroom.

But this story went decidedly off-script last year after U.S. officials, acting on Egypt's behalf, entered the fray. The feds informed museum leaders that they believed the mask was stolen, and they intended to use the courts to seize the artifact and return it to Egypt. But where some museums might have simply handed over the goods, St. Louis went on the attack, filing its own a pre-emptive lawsuit that claimed the statute of limitations had expired -- an aggressive challenge from an institution that has repeatedly defied calls to release its grip on this pricey piece of loot.