Were it not for the unbelievably naff ending, this could be one of the best espionage thrillers I've ever seen! As it is, Greta Garbo is still super as the Mata Hari style agent for the Czar out to obtain secrets from the Austro-Hungarian empire. After she shares a box with him at the opera, "Tania" uses her undoubted talents to seduce and dupe the decent, but rather gullible, "Karl von Raden" (Conrad Nagel) as he travels on a train, relieving him of some state secrets and costing him his career, his honour - and a lengthy prison sentence. Luckily for him, though, his uncle is in charge of…