Locked in the Abyss with the Tycoon

DramaBox synopsis

Avery returns home for her father's funeral and finds her stepmother has taken over, with help from her ex-boyfriend Sebastian, a mafia tycoon. She learns of a bank key to a money laundering network and plots revenge. Sebastian seems to protect her, but he is actually an undercover agent. They join forces and defeat the stepmother in a final confrontation.