Episode 4 of Miss Night and Day picks up the pace with Im Sun (Mi-jin in
disguise) starting her new job as Ji-ung's office aide. Mi-jin, excited for a
real job, gets a makeover for the occasion. Meanwhile, Ji-ung and Byung-duk,
underestimating Im Sun's capabilities, try every trick in the book to make her
quit, hoping for a younger replacement.
Their attempts backfire spectacularly. From typing at lightning speed to scaling mountains for a witness visit (thanks to her rock climbing side hustle!), Im Sun proves to be an exceptional assistant. Ko Won adds another layer of mystery by following Im Sun, only to witness her transform into Mi-jin, leaving him baffled.
The episode delves deeper into the acid attack case. Ji-ung and Byung-duk discover traces of Fentanyl in the suspect's blood, leading them to suspect a drug patch as the source. This discovery opens a new investigation thread – the illegal use and distribution of Fentanyl. Ji-ung, intrigued by the attacker's seemingly careless actions, wonders if he's looking for something or someone specific.
The double life continues to pose challenges. When Ji-ung asks Mi-jin to meet after work, he simultaneously burdens Im Sun with extra work. This comedic juggling act leaves Mi-jin barely making it to the meeting. However, Ji-ung, unaware of the chaos he caused, equips Mi-jin with self-defense tools, warns her about the murderer, and even adds himself as an emergency contact. Unbeknownst to Mi-jin, he also installs a GPS tracker on her phone, further blurring the lines between concern and control.
The investigation takes a surprising turn when Byung-duk discovers all the Fentanyl in the city originates from a high-end club. This leads to an undercover operation, with Im Sun surprisingly eager to join. Her knowledge of clubs once again catches them off guard, and they reluctantly allow her to tag along.
As the operation unfolds, the episode ends on a cliffhanger. Im-Sun, transformed back into Mi-jin, gains entry into the club using her youthful charm. However, her mission to gather evidence in the VIP room takes a dangerous turn when she's caught with a hidden camera. Meanwhile, Ji-ung, worried about the radio silence, forces his way into the club just as a guest attacks Mi-jin.
Episode 4 of Miss Night and Day is a whirlwind of comedic workplace antics, a deepening mystery surrounding the Fentanyl case, and the ever-present danger lurking in Mi-jin's double life. The cliffhanger ending leaves viewers eager to see how Ji-ung intervenes and if Mi-jin's secret will be exposed.