**SPOILERS**Dr. Penn Grogan (not Gorgan) is a biologist doing research at the Rockland University on medicinal use of tropical plants from the Western basin of the Amazon River in South America. One of such plants that can only be found in the Kichua jungle has big yellow flowers and is known locally as the vine of the soul . This plant has an unusual property of healing various kinds of wounds. Melinda Ghost Whisperer Gordon is visited by the spirit of a former colleague of Penn's at the Rockland University, the late Dr. Martin Shaer, who died under mysterious circumstances during their joint expedition to the jungle of South America. Penn and Martin found the vine of the soul during that expedition, but it appears that Penn was getting all the credit for that research afterwards.We get a glimpse of what happened during their trip to the South American jungle. Apparently, a guide from Machibuenga, an indigenous tribe of that region, agreed to take Martin and Penn on a tour of the jungle, hopefully to find the miraculous plant vine of the soul . Martin had to drink a Machibuenga ceremonial concoction in order to seal the deal. That concoction was a powerful hallucinogen and apparently contained Kamishita, a hallucinogenic plant. Martin was feverish before the trip but insisted on going anyway because finding that yellow flower/ vine of the soul meant a great deal to his and Penn's research. Martin fell gravely ill during that trip and told Penn to go get help and leave him in the jungle. When she came back with the tribesmen, Martin wasn't there and they only found his dead body after two days of searching. Penn was beside herself with grief because she and Martin were planning to get married after returning to the US. Afterwards, Penn was visited by Martin's spirit repeatedly and tortured by her feelings of guilt for some years, believing that she was responsible for Martin's death because she allowed him to go on the trip while sick and then left him for dead in the jungle. This is where Melinda comes into the picture.One night, Melinda sensed that something terrible was going on with Penn; she came to visit and was able to save Penn's life. The unending sense of guilt and visitations from Martins spirit caused Penn to attempt suicide by taking a mega dose of what appears to be tranquilizers. Melinda and Rick Payne called 911 just in time. Melinda, with some help from Martins spirit, unravels the mystery of Martins death. It turns out, he had been bitten by a mosquito carrying a dengue fever virus and had already been sick for three days before that unfortunate tour of the jungle. His death was inevitable and Penn Grogan couldnt do anything about it. This brings some relief and closure to Penn and she is able to get on with her life thanks to Melinda.Some notes: 1) During her lecture, Dr. Grogan says that her research can help find cures for such highly virulent diseases as Ebola, Marburg, and dengue fever, which, strictly speaking, seems like a bit of a stretch for a plant that can heal wounds. 2) At the beginning of the episode, we get the sense that Martin Shaer's spirit is haunting Penn Grogan as if trying to punish her for his death and for hogging all the credit for their joint research. He is seriously messing with her life and seems to even drive her to suicide. However, at the end of the episode, we find out that he was only trying to tell her that she shouldnt blame herself for his death and that he still loves her. If the spirit really cared about Penn, couldn't he have found a less violent and dangerous way of letting her know that she was innocent? Show less «