Tyler Durden: Now, ancient people found their clothes got cleaner if they washed them at a certain spot in the river. You know why?
Tyler Durden: Human sacrifices were once made on the hills above this river. Bodies burnt, water speeded through the wood ashes to create lye.
[holds up a bottle]
Tyler Durden: This is lye - the crucial ingredient. The lye combined with the melted fat of the bodies, till a thick white soapy discharge crept into the river. May I see your hand, please?
[Tyler licks his lips until they're gleaming wet - he takes the Narrator's hand and kisses the back of it]
Narrator: What is this?
Tyler Durden: This...
[pours the lye on the Narrator's hand]
Tyler Durden: ... is chemical burn.