To this day, tens of thousands of human bones from former colonies are stored in German museums. It is still unclear how they can be identified and returned. "The Empty Grave" follows two families on their arduous search for their ancestors: In the south of Tanzania, the young lawyer John Mbano and his wife Cesilia follow in the footsteps of his great-grandfather, who was executed by the German colonial army over 100 years ago. His ancestor's skull was brought to Germany for racist "research purposes" at the time; the family is still haunted by this pain today. Felix and Ernest Kaaya are in a similar situation: in the north of Tanzania, they are fighting for the return of their ancestor's bones and are going to the metropolis of Dar es Salaam to do so. Both families are wrestling with the thicket of German and Tanzanian bureaucracy, but are also receiving support from activists such as Mnyaka Sururu Mboro and Konradin Kunze, who are raising awareness of the issue in Germany. With their help, the Mbanos are finally received at the Foreign Office in Berlin, and then even Federal President Steinmeier comes to their hometown to apologize for the suffering inflicted. But the grave is still empty.

In their film, the German-Tanzanian directing duo Agnes Lisa Wegner and Cece Mlay tell of the traces and traumas that the former German colonial rule has left in Tanzanian families and communities to this day - and of the strength and self-empowerment of the bereaved, who are stubbornly fighting for a full investigation. "The Empty Grave" sheds light on a chapter of German history that has so far received little attention (including in film), and thus makes an important contribution to the long overdue reappraisal of German colonial crimes.