Suriya-starrer Tamil time-travel thriller "24", currently playing in cinemas, might have a prequel, according to its director Vikram Kumar."There's scope to work on a prequel. Audiences would like to know about the back-story of the twin brothers - Aathreya and Sethuraman - played by Suriya in '24'. We could establish their story in the prequel," Vikram told IANS.Although Vikram says he can't work on the prequel immediately, he might reunite with Suriya for the project next year."My next two projects are with actor Allu Arjun and Mahesh Babu. Only after I complete these two projects, will I be able to think of the prequel, which needs to be written first," he said.Meanwhile, "24", despite mixed reactions, is holding its ground at the box office.In its first week in cinemas worldwide, the film reportedly grossed over Rs.50 crore.Also starring Samantha Ruth Prabhu and Nithya Menen, the film is produced by Suriya and has music by A.R. Rahman.