After a bitter struggle to get a job, In-seong is faced with the painful reality. Moving back with his parents, he picks up a smartphone, which happens to say it’s CEO Kim Seon-ju of Silver Lining locked up in the phone. Is this some kind of new scam? Right then, the phone asks him to act for the CEO of Silver Lining.

Becoming a CEO overnight, In-seong corrects injustice with the absolute power he gained on the first day at work. As he tracks Seon-ju’s whereabouts on the day of the accident, suspicion against Ms. Jung, who may be a reliable ally or a deadly enemy, starts to grow.

While In-seong is confused by the texts and call from the unknown number, Seon-ju believes it’s a chance to track the caller. On the day of the meeting where Silver Lining’s enemies within and out are gathered, In-seong collects all executives’ phones using security as an excuse. As he calls the unknown number back, one of the phones rings.

In-seong and Se-yeon now shares the secret about Seon-ju trapped in a smartphone. The closer they get to the truth, the bigger the suspicion against him grows. Bumyoung’s executive director, Mi-ran’s advice, “Don’t trust Kim Seon-ju too much” keeps bothering In-seong, and he ends up checking out the place where Seon-ju went missing. There, he encounters a mysterious man.

After CEO Oh Bum-geun passes away, the fight to become his successor becomes more tense and the threat against In-seong and Se-yeon grows. In-seong wants to hire a security guard, but for some reason Se-yeon disagrees.

In-seong is determined to catch the real culprit after he sees how much Min-a misses her dad. He manages to corner Mr. Kwak, who had the answer to everything, but something unbelievable happens.

Witnessing death before his eyes, In-seong gets shocked. He goes back to his hometown to protect himself and his family, which are more precious to him than one billion won Seon-ju had promised. After realizing he wasn’t driven only by money, he comes back and starts investigating who attacked Mr. Kwak.

The subordinate takes Seon-ju’s smartphone from In-seong, but it was In-seong’s plan to catch the one behind him. Without Seon-ju, In-seong learns what burden a CEO must bear on his shoulders. Meanwhile, Seon-ju is taken to his enemies’ base by the subordinate.

With the help of Seon-ju inside the smartphone, In-seong discovers Seon-ju’s body in their enemies’ base. Everything starts to fall into place and In-seong finds out who is behind all this. Then he draws up a plan to play one enemy off against another.

As Bumyoung stands firm, In-seong holds a shareholders’ meeting to take down and bring the executive to justice. However, the power game turns out to be much more complicated than he thought. While In-seong is about to be removed from his post, MG starts searching for Kim Seon-ju alone.

Getting the CEO position back, In-seong feels the absence of his partner who has always been by his side. But there’s no time to be sad. In-seong negotiates a deal to get Seon-ju’s body back, not knowing what consequences it will lead him to.

Does he see what he believes, or believe what he sees? As In-seong finally solves the puzzle of “Kim Seon-ju, a smartphone, and Baro 4.0,” he prepares for the last battle with Bumyoung. On the day of the self-driving vehicle test-drive, In-seong sets out on a deadly race while the entire nation is watching.