What is happening

"Kavita what happened? Why are you behaving like this? Is this some sort of prank? I am not liking this", Surabhi got up from her seat. She was shocked to see her friend behaving differently. It was really unlike Kavita. Her expressive eyes had a blank expression. Surabhi could not understand why did Kavita say 'replace'?

"Replace," Kavita said again. She had not moved an inch from her place. She was not even blinking.
"What needs to be replaced? Why are you even saying replace? See it clearly Kavita. I am in no position to solve any puzzles," Surbhi was angry with her at the same time she was really petrified. Why was she hearing the same word again? First the phone, then the stranger at the door, and now her own friend - all had been saying 'replace'.
"Replace," Kavita said again. This time she had clenched her fist.
"Kavita cut it out. I am not liking this. Whatever prank you are playing just stop it now. Earlier I was scared but now I am annoyed. If you continue to behave this way I am going to ask you to leave," Surbhi informed Kavita loudly and in a firm tone. She was not going to tolerate this behaviour.
"Replace," Kavita spoke again. But this time the tone of her voice was different. It was almost as if Kavita was pleading.
"Kavita this is not helping. If you want to keep repeating just one word, remember the doors of this house would be forever closed for you. I am giving you one last chance. Drop it right now and behave normally," Surbhi picked up her on coffee mug and was heading to the kitchen.

As she turned around, she heard Kavita's voice again. This time it was a scream, "Help me".
Surbhi turned back to at her friend. Kavita has been standing. She was crying, her blank stare was gone. Her shell shocked expression had transformed into fear and agony.
"Kavita what is happening? Tell me. This is all so strange. Why do you keep saying 'replace'? Please Kavita tell me. I want to help you," Surbhi cried.
"Help me, Surbhi," Kavita said before collapsing. She hit against the table and spilled the coffee. Surbhi sprinted to help her friend.
"Kavita, speak to me. Can you hear me? Stay with me Kavita," Surbhi was trying her best to keep her friend awake. Kavita was losing her consciousness.
"Kavita, what is happening?" Surbhi was frantic by this time. Kavita's eyes were closed.
Surbhi tried everything that she had learned in the first aid workshop. She wanted to help Kavita. Though she was unsure if this was a good idea. She still could not understand why Kavita said 'replace' over and over again.

Finally Surbhi's efforts paid off. Kavita had regained her consciousness. Surbhi thanked god for saving her friend's life. But then she noticed. Kavita had opened her eyes. But there was the same strange blank expression on her face. Surbhi felt as if she was looking at a stranger rather than her friend. Surbhi asked softly, "Kavita, what is happening? Should we go to the hospital?"
Kavita opened her mouth and the words that came from her lips shattered Surbhi once again, "Replace".