Singer Sonu Nigam, who has sung a song in the short film "Raakh", says short films present many unexplored topics."Short films bring out many unexplored topics. I have sung a song in this film ('Raakh') which was liked by people. I am happy that the music is being appreciated," Sonu said at the success party of "Raakh" here. Actor Vir Das, who plays a negative role in the film, said he has never played such a character."My character in the film is something which I have never played in my life. It's something that I wanted to do for a very long time, but I never got an opportunity," said Vir, whose next year's films, include "Patel Ki Punjabi Shaadi" and an action movie.The actor praised his co-star Richa Chadha as well. "She is the soul of the film. Richa Chadha is looking lovely in the film."He also revealed the reason behind doing the short film, helmed by "Mastizaade" director Milap Zaveri. "I had done 'Mastizaade' with Milap. After that, when he gave the narration, I was surprised that Milap was making this kind of a film. He gave a great narration and so, I said 'yes' within five seconds," said the "31st October" actor.The film is a tale of vengeance.