Who is Narrator of "Tallis" from Ape and Essence and what is their importance?

The narrator of Tallis, which is in the first part of the novel, is employed at a movie studio with Bob Briggs. After he lunches with Bob, the narrator finds and saves the script for Ape and Essence by William Tallis when it falls out of a dump truck. The following week, Bob and the narrator travel to Cottonwood Ranch in Murcia, California to meet with William Tallis, only to learn that he died six weeks earlier.