Proof is the twenty-seventh episode of the anime.
Richard Brown meets with Dr. Reichwein. They talk about Karl as the person who found Edmund Fahren's corpse and that Richard might be able to see his daughter again. Reichwein tells Brown to not forget about never drinking alcohol again.
Brown remembers how he shot Stefan Joos, a 17 year old accused of several homicides, when he was a police officer because he drank while on duty and how he was disbanded from the police due to this. The memory of Joos starts chasing him. Brown investigates Karl, wondering if he is Schuwald's real son. Richard meets with his wife who tells him that his daughter does not want to meet him yet. Disappointed, Richard orders a whiskey, but leaves without touching it.
Johan advises Karl telling Schuwald that he is his real son. Karl refuses, arguing that Schuwald might think he is just another boy after his money. Johan insists that there must be something that can prove that Karl is Schuwald's son. Karl tells him that his mother gave him a rabbit's foot that Schuwald intended to give to his son when he was a child, but that he has no intention of telling Schuwald about it. Johan suggests keeping the rabbit's foot so that Karl will not change his mind.
Karl meets with his foster parents. Back home, Karl receives a call from Schuwald who tells him that it is a shame that he decide to quit his reading job and asks Karl to read him something for the last time. Karl reads to the tears and finds out that Schuwald had been behind the door all the time.
Schuwald shows the rabbit's foot to Karl, asking him why he did not tell him that he was his son earlier. Schuwald tell that it was Johan who explained him everything and announces that Johan will be working as his secretary from now on.
- Richard Brown
- Julius Reichwein
- Richard's ex-wife
- Karl Neuman
- Hans Georg Schuwald
- Helenka Nováková (flashback)
- Johan Liebert