Helena should of course say no. She doesn't know the man talking to her, she doesn't know Monsieur Bellivier, and she certainly isn't waiting for him. But, bored of life, and sparked by a whim, she says yes. Mancebo, a Tunisian shopkeeper, lives a quiet life manning his grocery near the Sacre-C?ur. But one day he is approached by a woman asking whether he will spy on her boyfriend, who lives in the apartment across the street. To his surprise, Mancebo agrees. As Helena and Mancebo's missions overlap, they realise that the City of Light harbours more secrets in its cafes and courtyards than its inhabitants and visitors could possibly suspect.