well what i think is like disha already said i will ruined your mother and than you would realized the lost of someone really close to you and eventually someone have heard it or may be gargi had find out that dk mother is in the metal hospital and as disha said to dk i would use your mother as a weapon to destory you and she would probably ask someone to kill her and dk must be thinking it disha who harmed her mother and from there misunderstanding begin