I'm currently binging Ich möchte zurückgehen in der Zeit by Judith Hermann. As it's been just released it's only available in German yet, but if you're able to read that I highly recommend. It's about Judith's own journey towards discovering the story of her grandfather and the traces this man, who was a convinced Nazi, has left in the family. The horrible shadow that drags way into the third generation, that no one seems to want to acknowledge.