This is a great episode, which keeps you guessing until the end. I would like to think I am pretty good at figuring out a Medium mystery before it is revealed, but this one was tricky.
Basically, their are two twin brothers; one has always been polite, meek and law abiding where as the other brother has been more aggressive, shady and engages in illegal activities.
The one good quality about the "bad" brother has been his love for his brother. He has always sought to protect his meeker brother from harm, even going so far as to beat up school yard bullies.
The wealthy drug dealer had both brothers killed or so he thought. The bad brother had gotten on the drug dealers bad side and the good brother was just in the wrong place at the wrong time.
The "good" brother managed to survive, although with serious brain damage. Still with me? OK, The dead brother had somehow managed to possess his now-mentally challenged brother in order to seek his revenge and to protect his brother from beyond the grave.
It is a great Medium story, which is wonderfully executed. I only have a few complaints about the episode.
First off all, it was obvious right from the start that Meghan Doyle was trying to make Joe so uncomfortable that he would want to sell his part of the company. It was probably a necessary story arch and it was well acted, it just was a bit too predictable.
Second off all, I was not all together clear how the "bad" brother was able to remain on earth as a ghost to not only get his revenge but keep the possession through his brother's prison sentence (so that his brother would think it was all a dream).
I would assume that the bad brother was probably going to go to hell, in keeping with the cannon of the series, but for some reason he was being allowed to stay and take his revenge.
Had he made a deal with the devil? Was he going to heaven because he had protected his brother all his life? I can understand the need in a series like Medium not to explain everything, but it would have been nice if they explained or hinted at how the bad brother was able to pull this off or where he was going when this was done.