Undercover Agents' Fierce Hunt

Special operative Nightingale and Interpol agent pose as a married couple, hiding identities, testing each other with blades pressed to throats. Identities revealed, they join forces to raid the Serpent Den stronghold. Betrayed by a mole, their partner loses memory and goes missing. Three years later, they cross paths again. She smiles: Captain Lu, this time I'll take care of you!