OMG I hope he can a least be free for a month.
I have a very over active imagination. I'm thinking that the king finding out that he is gone, will go and find the doctor's daughter.
He won't kill her, even worst, he will make her his empress. Meaning she can never leave the palace and would be even more trapped than the doctor was. This would cause the doctor to come back to try and save his daughter. By the time he hears about it and comes back, his daughter either
1. Kills herself after being trapped and hearing what happened to her father.
Or 2. is pregnant by the emperor in order to make some messed up family with the doctor or as died from child birth by the time the doctor returns