Hum Kaun Hai? is a horror drama inspired by the 2001 Spanish horror film The Others. The movie revolves around Sandra Williams (Dimple Kapadia), wife of Major Frank John Williams (Amitabh Bachchan). She lives in a palatial house with their children, Sara (Hansika Motwani) and David (Master Rehmaan), while Major Frank is away serving in the army. Sandra appoints three servants – Martha (Moushumi Chatterjee), Maria (Seema Raghmani) and Edgar (Abhijit Lahiri). As her kids are photosensitive, she instructs the servants to keep the curtains on every time, so that no sunlight enters the house. Things take a turn when Sara claims that she saw a group of people in their house, who co-live with their family in their house. Sandra doesn’t believe her initially but decides to investigate herself after she hears sounds and feels a supernatural presence. What might be the secret of these other people in the house? Who might they be?