Was it a genuine spiritual enclave? What happened to drive Ms. McNally and Mr. Thorson out of the camp and into the wilderness? And just why, in a quest for enlightenment, did Mr. Thorson, a 38-year-old Stanford graduate, end up dead, apparently from exposure and dehydration, in a remote region of rattlesnakes and drug smugglers?

When Ms. McNally and Mr. Thorson left the retreat on Feb. 20, after having participated for one year and one month, she had been its leading teacher. The monk who ran the retreat, Michael Roach, had previously run a diamond business worth tens of millions of dollars and was now promoting Buddhist principles as a path to financial prosperity, raising eyebrows from more traditional Buddhists.

He had described Ms. McNally for a time as his “spiritual partner,” living with him in platonic contemplation. What the other participants did not know is that before she married Mr. Thorson, Ms. McNally had been secretly married to Mr. Roach, in stark violation of the Buddhist tradition to which he belongs.

Even the manner in which Ms. McNally and Mr. Thorson left the retreat adds a fresh turn to an already twisty tale. It came days after she made a startling revelation during one of her lectures: she said that Mr. Thorson had been violent toward her, and that she had stabbed him, using a knife they had received as a wedding gift.