Gerta's family was split up the day the wall went up. Her father and a brother ended up in the West and her mother, other brother and herself are stuck in the East. For 4 years they live, get along, survive but their father's involvement in resistance actions makes the whole family suspect.
When Gerta spots her father on a platform near the wall she thinks he is sending her a message to dig. So she and her brother start digging in an abandoned bunker under No Man's Land. But time is running out and suspicions are running high. Can they escape?
I really enjoyed this book - lots of action, intrigue, and courage. A good historical novel.