Ouji no Honmei wa Akuyaku Reijou Temporada 1 Episódio 5

Diana is locked in a prison by Spica. Not understanding why she was trapped there, she searches her cell and finds Dianas diary. Whats more, there was a shocking truth written in it! Meanwhile, Sirius, who came to the Diafell household to see Diana, feels something is off when Diana is not there.