Heart Attack or Murder?

Arjun – Season 1

Sandhya reveals to ACP Arjun that her husband Hiten is planning to kill her. Sandhya dies of a heart attack. By the time ACP Arjun reaches her house, Hiten has already finished the funeral. Arjun then finds a botany book in Hiten's girlfriend Gowri's house. What will Arjun find?