Director Ayan Mukerji is all excited for one of his most ambitious project Brahmastra, and hopes the film becomes "the biggest success of his career as well as of the film industry".

"It's the biggest project of my life. All my hopes are pinned on this film. I hope it becomes the biggest success... I am very excited about the cast but I hope the film gets even bigger than the cast."

The cast - Amitabh Bachchan, Ranbir Kapoor and Alia Bhatt - all come together "because of the story and theme of the film", Ayan said, speaking at the Jio MAMI 19th Mumbai Film Festival.

Earlier tentatively titled Dragon, Brahmastra was renamed and announced by producer Karan Johar only two days back on the 75th birthday of megastar Amitabh.

Ayan is rather close-lipped on any more information about his "dream project. "I will not be able to give information right now but all I can say is, this film is a modern-day film."

"It is set in India as it exists today but the name of the film is called 'Brahmastra' because the energy, wisdom, and powers in the film come from ancient India.

"As far as costumes are concerned, there are some which may not be the way you would expect them to be".

On working for the first time with Amitabh Bachchan, Ayan said: "It's a great honour for me as it would be for any filmmaker to be working with him, in his 75th year especially. 

"Ever since this film was conceptualized, I wanted to approach him for the film and make this film with him. So I am very happy that he is part of team Brahmastra."

Brahmastra is a fantasy adventure film, the first part of a trilogy and it will hit the screens on August 15, 2019.