The tunnel is the main symbol in the book. It is a space in which the siblings can work together to plot out a future for themselves, one that involves freedom and family reunification. It is also a liminal space, as it’s being built under the Death Strip, that span that separates West Germany from East Germany. Further, Gerta and Fritz are surprised to discover in their tunneling that their father and brother are tunneling from the other direction to reach them. They end up meeting up in the middle and journeying out together. On the literal surface of the Death Strip, there are only negative connotations; beneath, however, there is hope. The tunnel is also a space in which unlikely conspirators come together—Anna and her family, who previously resented Gerta and her relatives; and Officer Muller, who previously harassed Gerta for looking at and beyond the wall. Digging the tunnel is arduous, dangerous work full of complications but it is also a project that inspires bravery and unity.

Though the garden is a front for the tunneling, it is a space that attracts two visitors who eventually assist Fritz and