After making a thriller, filmmaker Sriram Raghavan now wants to experiment with other genres and says his next directorial venture "Happy Birthday" will be a sci-fi movie.

Raghavan, who first made "Ek Hasina Thi" with Saif Ali Khan and Urmila Matondkar, is right now gearing up for the release of his spy thriller "Agent Vindo". Starring Saif in the lead role. The film is releasing Friday.

"I had finished certain amount of script of 'Happy Birthday'. I will reopen it in next two months. I have not worked on it for a while. Till 'Agent Vinod' releases, I am in this world. After that, I will think about it," Raghavan told.

"'Happy Birthday' is a science fiction film. We wanted John and Aishwarya for it-two-and-a-half years back. Now I don't know what the status is," he added.

However, the reports were that "Happy Birthday" was to go on the floors even before "Agent Vinod", but Raghavan said: "I was not happy with the climax of 'Happy Birthday'. I was not sure about it earlier.

"I thought I will shoot the climax and leave it. But that was too risky to leave it like that. By the time I cracked the climax, I had two other projects in my hands including 'Agent Vinod'," the 48-year-old said.