When frozen bodies are found in Nevada floating in water, the BAU's investigation leads them to suspect that the victims were part of a cult that could be behind the deaths, in an episode entitled "The Forever People"
Hotch: A sniper can wait up to 72 hours without sleeping. Mays: Seriously? Rossi: That's part of their training. They can stay awake for 72 hours and remain completely focused on their target. Mays: How? Hotch: By using a mental exercise called "fantasy integration". A sniper creates a scenarios involving a target that keeps that person at the forefront of their mind. Morgan: Often they'll imagine a place where they're with the target, doing something together that takes time. For example, building a car. JJ: For some, the fantasy begins the minute they're assigned a target. Then nothing will distract them.