Major twist in Yeh Hai Mohabbatein: Roshni runs away from the Bhalla house

Roshni leave the house secretly. Ishita finds an emotional letter written by her. It upsets the Bhalla family. While, Raman is on mission to find the culprit behind Tanya's case. Param is a step ahead. He threatens Raghav's wife to stay mum on the matter or otherwise he will kill her daughter.