Wali, 11, has a scale. He makes money by weighing passers-by on a busy street in Kabul. He has teamed up with chewing-gum vendor Basira. Like him, she has lost her father. Business is bad, but luckily Wali lives rent-free in a cave with his mother. One day Wali comes home to find that they are being evicted. Basira must find a way to help her friend.