An Iranian nuclear scientist who vanished in June 2009 resurfaced Monday night at the Pakistani embassy Washington. Tehran has claimed that the scientist, Shahram Amiri, was kidnapped by the U.S. during a pilgrimage to Saudi Arabia last year. (American officials deny the charge.) Earlier press reports said Amiri, 32 years old, had defected to the U.S. to work with the CIA on undermining Iran’s nuclear program. The story is further complicated by Amiri’s appearance in Web videos; in one, he claims he was kidnapped, in another he says he’s just studying in the U.S. On Tuesday, Iranian state-owned media reported that Amiri went to the Pakistani embassy demanding to return immediately to his homeland. The scientist’s appearance could become an embarrassment for the U.S. as it seeks to stop Iran’s nuclear program.