Do Ki continues to hunt down the bad guys; he and Sung Chul secretly assist a father who is looking for his lost son.

A young scammer who targets the elderly leaves an older woman in debt, and she comes to Rainbow Taxi for help; outraged, Do Ki and the team devise a plan to stop the scammer for good.

Rainbow Taxi launches its operation to punish Sang Gi and uses Sung Chul as a wealthy old man to lure him; Sang Gi falls for the trap.

Do Ki encounters a lost girl on the streets; he takes her to Rainbow Transport out of concern and discovers that shady people are after her.

Rainbow Taxi Company and the taxi driver, Do-gi regain justice that Korean society has lost by seeking revenge on criminals who get away with their evil deeds.

이서의 발자취를 뒤쫓던 무지개 운수 팀은 최근 일본에서 새로이 떠오르는 범죄 조직의 우두머리인 마쓰다를 눈여겨본다.