Let's start with the title - "Between Heaven and Hell" - it's bland, and tells us nothing about what we are about to see. Really this ought to be called something like Monkey's Adventures in the Land of Greedy Dicks, at least then you would sort of know what you're letting yourself in for.
The story itself, such as we may charitably call it, sees the pilgrims visit a Buddhist shrine where, for a donation, visitors may crawl through a hole to get a glimpse of paradise. Tripitaka instantly recognises it for the obvious con it is, but because there wouldn't be an episode if he didn't then he goes along with his disciples' requests to visit it.
Sandy gets stuck halfway through the hole, meaning he can't get out and nobody else can go through after him. None of the disciples are able to use their magic to free him - again, the only reason for this is to avoid short-circuiting the plot of the episode - so they will have to break the shrine's wall to get him out.
The Buddhist priest demands an outrageous sum, 100,000 of the local currency, to pay for repairs and as compensation for the loss of the shrine's income in the meantime, and then we get one of only three (small) good bits in the episode, when Tripitaka cuts through the priest's euphemisms and calls this what it is: a ransom.
There then follows a series of unfunny escapades in which they try to raise the money, with Tripitaka and Monkey acting completely out of character all the while. Tripitaka sells the horse (though gets him back by the end of the episode), and Monkey tries to pawn his magic wishing staff and flying cloud but finds no takers.
Eventually, after 25 minutes, we get to something more interesting (though that's not saying much). Pigsy is employed to change his shape and act as a decoy princess, to draw assassins away from a real princess. Initially unwilling to risk his own neck, he is tempted by the offer of half the money needed to save Sandy.
We then get the second good bit of the episode, which is the facial expressions of the actress playing Pigsy-as-princess, both amusing and characterful, and conveying well that this is not the real princess.
Monkey, meanwhile, is employed by the assassins to kill the princess, having been promised exactly enough money to free Sandy. Disguised, he attacks Pigsy-as-princess and they fight. The trope of two friends, both disguised, fighting each other, is an old one and a good one - I recall a similar tale involving King Arthur and one of his knights - but it is completely wasted in this atrocious episode.
Pigsy gets in a lucky blow and stuns Monkey, and his mask slips. Once the explanations are over, Monkey comes up with a plan to cheat the assassins out of the money - a simple one, Pigsy will just pretend to be a dead princess.
This leads on to the last good bit of this episode (and if I'm making it sound like having three good bits in an episode is a lot, please remember that it really, really isn't when taken with all the piss-poor nonsense that surrounds it) when both Monkey and the assassins double-cross each other at the same time.
Sandy, meanwhile, has manages to get out of the hole by himself, simply by starving until he was slim enough to escape. When Tripitaka, Monkey and Pigsy go back for him they find the priest still demanding the money. Monkey has, like the audience, had enough by this point, and gives the priest a beating for his greed instead.
I can see no evidence that this episode was left out of the original TV run for being too violent or gory. I think it was left out because it was shit.