Ferren founded Associates & Ferren at the age of 25 to do work at the "crossroads of design and science and entertainment." One of the first projects was for Broadway play "The Crucifer of Blood", a Sherlock Holmes mystery that starred Glenn Close and won Ferren a Los Angeles Drama Critics Circle award. The production featured a "shattering display of thunder and lightning", which got the attention of director Ken Russell, leading to Ferren's first prominent assignment as Special Visual Effects director on a major Hollywood science-fiction film, Altered States.