The captivating `Shivaay` trailer is out but the mystery remains intact. The dream project of actor-director Ajay Devgn looks mesmerizing  with a compact, thrilling plot, mind-blowing chase scenes involving cars, trucks and choppers and of course, Ajay Devgn who is back with a bang in the snow-capped mountains. Shot extensively in Bulgaria, `Shivaay` seems to be a nail-biting thriller that is yet to throw light on the intense story that also stars child actor Abigail Eames, Sayyeshaa Saigal, Ali Kazmi as Major Khan, Vir Das and Erika Kaar. The on-the-edge action scenes over the mountains and down the cliffs are promising . Directed and produced by Ajay Devgn, `Shivaay` will hit theatres around Diwali on October 28, 2016.