Bipasha plays a dual role of conjoined twins in the film.

The trailer of Bipasha Basu and Karan Singh Grover's much-awaited horror film “Alone” was unveiled late Tuesday night and has got an overwhelming response from the audience. With over 4.4 million views on YouTube, it has set a new benchmark by becoming the No.1 video in less than 48 hours.
This is a feat in itself for big banners that are featured on YouTube channels with huge subscriber bases, but Panorama Studios, the film's presenter, is a new company making its debut production.  
The film revolves around the novel concept of conjoined twins where Karan Singh Grover's character Kabir falls in love with one of the twins and then a series of twists and turns take place.
This intriguing trailer has managed to entice the viewers' curiosity. Audiences have given a double thumbs-up to the trailer and now, they are quite keen to watch the movie.
Directed by Bhushan Patel, “Alone” is produced by Kumar Mangat, Abhishek Pathak, Pradeep Agarwal and Prashant Sharma, and is slated to release on January 16, 2015.

Source: TOI