'Sandhya' is a story of Dr. Singhania (Ashutosh Rana) who runs a mental institution. As the film begins, you witness the murder of Dr. Singhania's entire family. Dr. Singhania loses his mind after witnessing the murder of his family. Then he is eventually admitted to his own hospital and he stays there till he recovers. After coming back from the hospital he decides to convert his home to a nursing home and title it \"Sandhya\", which means twilight.

But Dr. Singhania soon realizes that he can't live without his family and he becomes more depressed as the anniversary of his family's death gets closer. It is then that he decides that he must do something about his agony. After a long process of thinking he finally comes to the conclusion that he must end his life, and to do so he hires Jaggu (Jackie Shroff) to kill him on the same date when his family was killed.

Soon the day of the murder comes nearer and it seems like everything would go as planned but it turns out to be much different for Jaggu. He is trapped in an unprecedented web of deceit and he soon realises that something very bad is about to happen. Aptly titled 'Sandya', which means twilight.