I remember a conversation from long ago, before I left my home world, before the Shortening of the Way...
"Do you know of the Water of Life? The bile from the newborn worms of Arrakis."
"I have heard of it."
"It is very dangerous. The Bene Gesserit Sisterhood use it to see - within. There is a place...terrifying to us, to women. It is said a man will come - the Kwisatz Haderach. He will go where we cannot. Many men have tried."
"They tried and failed?"
"They tried and died."