In the Malasaña neighborhood of Madrid, Spain in 1976, a nation rife with political turmoil, the Olmedo family moves into a new apartment. They discover that the walls of their new home hide a mystery: they can hear everything that is said in the adjacent apartment, which is occupied by an unmarried couple clinging to the deteriorating fringes of the bourgeoisie. The two families attempt to live their lives amidst the political upheaval that threatens to bring Spain to its knees, but the secrets they overhear and the relationships they forge will change them forever.