In the next episode of "Supernatural," Sam Winchester (Jared Padalecki) and his brother Dean (Jensen Ackles) investigate the ghost of a demented doctor.

The trailer for the upcoming installment titled "Advanced Thanatology" was released just recently and showed Sam and Dean preparing to go for an investigation. "When was the last time we worked a case? Just you and me," Sam asks his brother who just nods in agreement. They usually handle a case with the help of other people and even angels. This time, they are going at it alone as they go undercover as FBI agents and ask a lady some questions at her house. Later, they come into contact with the ghost in question, who was an insane doctor in his former life. Apparently, the ghost is connected to a number of strange happenings and poses a potential danger to the living. They hit the ghost who just suddenly disappears unscathed.

The entity was fond of drilling and torturing his patients in his human life. It seems it is back to its old habits and could very well kill someone unexpectedly. It remains to be seen how the Winchester brothers will contain this ghostly threat. Meanwhile, their friend Castiel (Misha Collins) manages to find his way back to the brothers. He was trapped in another dimension when he was suddenly killed last season.

In the previous episode, Sam and Dean defeated Buddy (Niall Matter), a psychotic shapeshifter who wanted to torment his similarly shapeshifting girlfriend Mia Vallens (Rukiya Bernard). Sam was able to shoot and kill Buddy with the help of Jack (Alexander Clavert) who used his telekinetic powers to knock him against the wall. In the end, Vallens was saved.

"Supernatural" season 13 episode 5 will hit the airwaves on Thursday, Nov. 9 at 9 p.m. EST on The CW.