Isaac and the Black Sword Knights are responsible for training the Maihama army. While he's in Maihama Isaac gets to know the new crown prince of Maihama, a young boy named Iselus.  Iselus respect looks up to Isaac and respects him.
At a party for the crown prince's birthday, assassin's make an attempt on his life.
But I thought you had a son.
Aber sagen Sie mal, haben Sie
nicht auch einen Schwiegersohn?
Pero pensé que tenía un hijo.
Il me semblait pourtant
que vous aviez un fils ?
Credevo avessi un figlio.
Mas achei que você tivesse um filho.
Но ведь у тебя, насколько я знаю,
был сын, разве нет?