Essene séance?

SIMON SAYS: AN INTERESTING PLAY NOW SHOWING IN BOSTON: Simon Says See Schaffer's Séance (Jules Becker, MySouthEnd.com). Excerpt:

Speaking through James, Simon describes the soul as "a suit of clothing" and speaks of having arthritis in a previous life. Tellingly, he calls up details about the Essenes, the tightly structured groups associated with the Dead Sea Scrolls-Jews described here as "under but not with the Romans." To hear Simon, he himself was an Essene cared for by a surrogate mother named Rachel. As he continues, he identifies Essene prophet Nathan as the greatest of all, but not false at first. Murder mystery elements include the possibility that Nathan murdered Rachel's late husband Aaron.

Josephus mentions a dream interpreter named Simon the Essene in Jewish War 2.113. But I can't find any reference to an Essene prophet named Nathan.