Shaken by an abusive experience, a young woman with an intellectual disability takes up the services of Kim Do-gi and his team of revenge seekers.

With an eye on payback, Do-gi transforms into a deep-pocketed customer to trick Kang Maria's tormentors. Kang Ha-na wonders about a missing criminal.

Do-gi goes undercover as a high school substitute teacher after receiving a call for help from a student who is being severely bullied.

The three bullies' attempts to mess with Do-gi come to a halt when they realize he possesses video footage that could ruin their lives.

While Ha-na looks into allegations of employees suffering physical abuse inside a powerful tech company, Do-gi poses as a new recruit there.

To gain access to Park Yang-jin's inner circle, Do-gi focuses his efforts on infiltrating a key department within the company.

As the truth behind an exploitative incident involving An Go-eun's sister comes to light, Do-gi sets out for revenge. Ha-na shows up with a warrant.

Do-gi finds himself in danger after Yang-jin gives him a cruel test of loyalty. Go-eun returns to locate and destroy the data servers.

Ha-na grows suspicious when she finds Do-gi's ID card at the scene of the explosion. Meanwhile, the team takes on a phone scam case.

Do-gi dons another disguise to lay his charms on the leader of the voice phishing operation. Ha-na keeps a close eye on the team's whereabouts.

Despite the disbandment of Rainbow Taxi, Do-ki is still out there going after bad guys. While keeping it from the rest of the members, Do-ki and Sung-cheol secretly help out a father who is searching for his missing son. To confirm his whereabouts, Do-ki sets off abroad to a foreign country to accomplish his first mission.

Do-ki successfully infiltrates Cheongeum with the help of his old crew. He pretends to be an abducted recruit but secretly searches for Dong-jae. During the search, he runs into Lim Bok-ja. He uses her revengeful anger to make it easier to find the missing boy. Just when he is about to capture the mastermind, a mysterious gun shot interrupts his arrest.

An elderly woman visits Rainbow Transport as a victim. She owes a lot of money because of a young scammer who only rips money off old people. Do-ki and the team get infuriated upon seeing this and set up a plan to prevent this criminal from ever scamming the elderly again.

Rainbow Transport officially begins its operation to bring punishment to Sang-gi. The plan mainly depends on Sung-cheol being a loaded old man as bait. As soon as Sang-gi sees this and plans to scam him, he does not realize the karma that he is about to face. Meanwhile, the secret organization Do-ki is after is also keeping an eye on Do-ki as well.

Do-ki runs into a stray little girl on the street. Out of concern, he takes her to Rainbow Transport and learns that suspicious people are after her. Do-ki and the team tries to infiltrate Feel Consulting and get some info on Kang Pil-seung to find out why he is in search of this poor little girl.

Do-ki and Go-eun get busted by Pil-seung for putting up an act. However, Do-ki manages to win back his trust by acting how desperate he is for a house. Now that they are back on track, Do-ki learns how Pil-seung is able to help couples get housing by using children. Disgusted by his ways, the team is determined to bring down Pil-seung at all costs.

The next client is a woman named Lee Jin-hee. Her beloved sister Jin-sun is suffering from a terminal disease and is relying on a cult to cure her. To save her from the cult and to take down its leader, Rainbow Transport begins service. However, Do-ki is not the one who will be infiltrating the cult this time.

The plan to destroy Ok Ju-man is now set. The only thing that remains is for Ju-man to take the bait. Although he does not have faith in any kind of religion, the Rainbow Transport team makes it seem believable. By setting the perfect scam, Ok Ju-man becomes faithful to the fake cult that Do-ki makes.

A smelly drunk man protests alone in front of a big hospital. He claims that his daughter is in a coma due to a surgery malpractice. Although Rainbow Transport took him in as a client, they are not sure whether this is an actual case or just an accident. Before they start anything, Do-ki looks into Ahn Young-sook, the director who performed the surgery.

Do-ki becomes a patient himself to infiltrate the operating room. When he is put to sleep, Go-eun finds out that there is a proxy who does the actual surgery while Young-sook goes somewhere else for a drink. Now that the team knows she is a complete fraud, they set up a meticulous plan to bring the witch down.