Kalki Koechlin is gearing up for the release of her first horror movie ‘Ek Thi Daayan’.

“I have not done a horror film before. The promotions start in two days, so prepare to be scared,” said Kalki Koechlin to IANS.

‘Ek Thi Daayan’ is tells a story about a Magician (played by Emraan Hashmi) and a witch. Kalki Koechlin said that audience will have a tough time guessing who among her, Konkona Sen and Huma Qureshi is the real witch.

“’Ek Thi Daayan’ is ... about a witch and a magician. The mystery is that there are three possible daayans and you guys will probably have lots of competition trying to guess which of us is the daayan,” said the actress.

‘Ek Thi Daayan’ directed by Kannan Iyer is produced by Ekta Kapoor and Vishal Bhardwaj.  The movie is scheduled to release on April 18.

Kalki Koechlin, who is currently busy shooting Ayan Mukerji’s ‘Yeh Jawaani Hai Deewani’, said that Ranbir Kapoor is great fun to work with.

“We are still shooting Jawaani Deewani. We will soon be going to Kashmir. Ranbir is good when he is on his best behavior. I don't know what he puts in his breakfast, but he has too much energy. We have a lot of fun on the set,” she said.

‘Yeh Jawaani Hai Deewani’, produced by Karan Johar, also stars Deepika Padukone.

The eagerly awaited movie will hit screens on May 31.