I think Lange's character Marsha has left permanently. The bar was partly Marsha's source of income as well as free whiskey, that along with Uncle Pete's death makes it seem like that was her exit.
I actually think Alda and Lange will return, with the former doing so as a ghost or figment of several people's imagination, and the latter just popping back up.
Remember, they're credited as part of the main cast ("with Alan Alda and Jessica Lange"), so I'm sure we haven't seen the last of Pete and Marsha.
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To be honest it would be pretty funny if the show just completely shifted gears and became a silly comedy with ghosts in it. I've always thought it would be a a funny concept for a show to have it switch genres every week. But obviously that's not going to happen and I'm mostly just rambling, sorry.
I know your just hypothesizing, and yeah it would be funny and weird.
But in reality it would go against the entire concept of the show.
It's a "as real as it gets" type show, as evidenced by the political/philosophical/racial/family dynamics/illness type conversations that frequently occur.
It would be a complete 180 to suddenly introduce supernatural themes.
Doesn't have to be a ghost. Uncle Pete can comeback in fantasy sequences, dreams and even Pete's hallucinations, which could be truly poignant and powerful, considering that was his dad.
Marsha I don't believe is through, either. I think C.K. has set up something for her character. I think she's going to return broken and desperate for a drink and old memories.
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