It involved cannibalism of someone I must have known, I just wanted cave exploration not Aztec rituals.
I was at a novenario. A prayer that is held for 9 days after a person has passed away is hosted by the deceased's family. It's just as much to give them support as it is to give them, both the family and the deceased spiritual help. At the end of the prayer each day the deceased's family will usually offer some food to the guests. The guests will also typically bring food as well and a small feast will be held. The feast will be a large one at the end of the novenario.
The one I was at was the final day of prayer. But it was done unusually. Before the prayer was started, a number of large, flat, and very smooth yet stones that looked like shale were combined into a rectangular slab at the center of the room. The body of the deceased was then placed on the slab, fully dressed. The prayer began with all of us kneeling down and holding hands around the body (the prayers do not ever go this way). It continued that way until the prayer was over.
For the feast the body of the deceased was then prepared and cooked. It seems like this happened right there on the slab. I specifically remember the sight of his torso and legs that were flayed and roasting on the slab. Part of him was made into pozole, a type of stew. Other parts of him were made into al pastor and served with tortillas. I partook of these foods and was eating the pozole until I woke up.