I Was Possessed by the Mad Lady's Body That I Serve!

Bella, a poor, tormented maid bullied by her masters in the duke’s household, was pushed off the rooftop by a veiled figure. When she regains consciousness, she finds herself possessing the body of the duke’s mad daughter who had been sick for years. Bella decides to use this newly acquired identity to uncover her murderer and take revenge! But can she pull it off while avoiding an arranged marriage to the rumored monstrous count of the Stuel kingdom?

(Source: Tapas)