The makers released OM trailer, offering glimpses into the world of red sandalwood smuggling. Dhanush leads the action thriller, with Sai Pallavi and Mammootty playing important roles. Ahead of its release, the makers of OM: Chapter 1 — Udhiram: The Blood Wood unveiled the film’s trailer on Friday (November 13). The film stars Dhanush, Mammootty and Sai Pallavi. Written and directed by Rajkumar Periasamy, the Tamil drama centres around red sandalwood smuggling.