In Madrid in the 1920s, four women working in the national telephone company quietly connected emotional storms and changes in destiny through the switch lines.They wander in love, struggle in jealousy, and also explore themselves and find belonging in the modern workplace where they are emerging.What comes from the other end of the phone line is love words, or betrayal; it is a command of work, or the cry of the times.Their story is a symphony of freedom, desire and awakening, quietly playing on the edge of a turbulent era.