Arsène Lupin is extremely popular among the population, because he allows the needy to share in his acquired wealth. Before entering the service of the German Emperor Wilhelm II, he removes his vault in Alsace, steals two paintings of old masters, steals valuable gems and calls out to the police prefect to avoid his arrest. But this time he risks being seriously recognized. Lupin must once again use his fine intellect to deftly escape the situation.
Bienaimé, a modest postman, in love with Janine, the village postmistress, does not know that he is the illegitimate son of the old Baron de Mondésir. The Baron dies and in happy amazement, Bienaimé finds he is the sole heir to the deceased's estate. But he should be careful, for two crooks, Waldemar and Erika, are after his newly-acquired wealth.
Serenade represented the return to the screen of international favorite Lillian Harvey after an absence of two years. Based loosely on the life of composer Franz Schubert, the film casts Bernard Lancret as Schubert, Harvey as his dancer sweetheart, and Louis Jouvet as a possessive Baron who has his own designs on our heroine.
