“I’ll tell you about The Yellow King,” the man said. And it all came undone.

Throughout “True Detective,” Marty Hart has harped on the detective’s curse, that the solution to the mystery is often right under your nose but you still can’t see it. By the end of “The Secret Fate of All Life,” as Detective Rust Cohle creeps through the abandoned husk of Light of the Way Christian Academy, where he finds hieroglyphs of dead children and a thicket of dusty devil’s traps, we have to wonder if he knows he let the answer slip away....