This is said to be the sister adaption of the 'Who's The Murderer' series that He Jiong is cast in as well.
Instead of solving cases where there is a dead body, cases of kidnapping or missing items, mysteries are to be solved in this show. There will be a detective, a keyman (who can lie) and the rest are players, there might be some episodes where there is no detective so they will not have first round of voting.
The sets for the keyman are very realistic as they are built for each episode and the cast goes through the story themselves. The props are very real and fitting for the set designs. In this aspect, it is very similar to the Who's The Murderer: Season 3 where the hotel of the first episode was built just for the show.
This show goes through the same format as 'Who's the murderer';
The case will start off like a story until some incident happens. All players will tell their alibis for their timelines. They will be split into groups to search for proof and evidence for 10 minutes. They will then head to the discussion room and explain or ask questions on the evidence that they have found. The detective will then make his/her first decision on who is the keyman.
The show will carry on with all players finding evidence together and discovering more of the story as time passes. The detective will then have a one-on-one interrogation and sometimes will ask the players on who they suspect is the keyman. The search will carry on for a little while more before they do a group meeting on settling the final facts they know.
The players are given time to have solo searches for additional evidence that they might have missed on before heading to make their decision on who the keyman is. The votes of all players are calculated and the player with most votes will be chosen as the keyman.
The chosen player will then insert their key into the machine that reveals if they are indeed the keyman. If the machine lights up and turns on, the players have won and found the keyman. If the machine does not turn on, they have failed in finding the real keyman and he/she gets away with it.