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"
Reid: There's an old Buddhist saying that, when you meet your soulmate, remember that the act to bring you together was 500 years in the making. So always appreciate and be kind to each other. Lewis: That's lovely. Reid: There's a corollary for friends. When you meet a true friend, you will be bound together though space and time for 500 years.