in one place we have the Taxi Rainbow Team who every one of the squad have experience at first hand what its like to lose a love one in a very violent way. they know how the system does not help the victims and consequently the family of the victims. therefore they have to spend their days knowing they will never get justice. that the system was never there to help the victims but to protect the bad guys. with that they decide to take revenge in the name of those who can't, with their own methods, outside the law, their ways can even be said to be derived from morality;

in the other hand we have Prosecutor Kang Ha Na who believes bad guys needs to get punish through law and the law only, any other method will make you as bad as them. she is the shining example of what "justice" is —rightfull, law abiding—. you see, she's the good cop, the one that follows the rules, can't get corrupted and works hards to get the villains in jail. she's different from the others —which can include even her sunbae— because she can see what is "right" and what is "wrong". therefore for her The Taxi Rainbow Team is in the wrong, The Taxi Rainbow Team broke the law so they deserve to be punish as well. in fact this particular 'case' of a Taxi Driver who kidnaps bad guys deserve her full attention. because for her if you don't follow the law —or rather, the system— then you need to be judged.

yet she watches over and over again how the system she so much believes in is unreliable, unable to actually help those who need it and rather benefits those who don't deserve it. but you see for her it's not the system, it's the people who utilizes the system in benefit of the bad guys. even when she's the one who requires the service of The Taxi Rainbow Team she's unwilling to accept that is the system that it doesn't work and has never worked. she even managed to give them a lecture about how wrong their methods are and gets to be the one who helps them to punish "rightfully" the bad guys at the end of the show.

the Taxi Rainbow Team finally decides —with a little bit of help of Prosecutor Kang Ha Na— that bad guys go to jail because apparently the prision reform is "helpful" and therefore they are respecting the law. that their ways have crossed the line so there was no need anymore for the company to continue with that project. that bad guys are to be left to the police because apparently they actually are "useful". and with this new "realization" they part their ways....

....but no longer after, they reopen the The Taxi Rainbow project?

does it means that they realize —once again— that the system truly will never be there for the people? that as long as they live in a capitalistic society the system would be there only to give profit to the powerful and therefore the non privileged are set to suffer? that at least the little support they offer help the victims in a way....?

....yet we find that now Prosecutor Kang Ha Na is part of the team. does it means then even though they will follow with the Taxi Rainbow activities they'll do it according to the law and therefore they are given their hopes on this flawed system?
the fact that Ahn Go Eun decides to become part of the police reinforces the idea that they have decided somehow to believe in the system, making then this just another cop propaganda show and therefore undermining how these cases both in here and real life are wrongly handled, which makes you wander then what's the point of this show?