Here are my ideas for the next three seasons of True Detective.

Season 3: Nancy Drew and the Hardy Boys solve the Texas Yogurt Shop Murders
Season 4: Brad Pitt and Morgan Freeman track down the Zodiac Killer. Or it could be a Western season where they get dispatched to Utah to find out who did the Mountain Meadows Massacre.
Season 5: Dennis Frantz comes out of retirement to hunt down David Caruso and bring him to justice.