S01E19 — The Doctor Has Arrived

Oga returns home after being defeated by Tojo to find that Hilda has returned from the Demon World with the imperial doctor, Forcas Rachmaninoff, and his assistant, Lamia, to help determine the cause of Beelzebub's illness. He diagnoses the illness as King Fever and when Beelzebub was trying to draw out massive amounts of demonic power, he accidentally severed the link between him and Oga and found Tojo similar to Oga and connects to him. Oga begins a treatment to try and reconnect with Beelzebub and enters a dream world through the effects of a Demon World drug that is shot into his head where he eventually finds a sleeping Beelzebub in the middle of several inscribed circles that are shrouded in an electrical field. After about 6 hours of treatment, Oga still has not waken up and Lamia assumes that he has died and becomes happy. Oga suddenly wakes up and spanks Lamia and claims he is teaching her some manners. Hilda asks Oga how he feels after having gone through the hard part of reconnecting with Beelzebub and Oga says he is in the mood to get Beelzebub back.