Contestants will then be divided into two teams of six and compete in various Investigation mission games in order to obtain clues about the Master Key owners.

The two Master Key Owners will have to avoid getting voted the most and must find each other in order to win the top prize.

Contestants, as stated above, will then be divided into two teams of six and compete in various investigation mission games in order to obtain clues about the Master Key owners, while each trying to individually win the votes from other players by claiming himself/herself as the Angel Master Key owner.

The Devil Master Key owner will also gain an additional vote each time his/her team win an Investigation Mission game.

A further change is implemented on episode 9 of which the number of Devil Master Key owners is increased to two and there is only a player randomly assigned with the ability to cast 3 votes.

Each Master Car has one mission and if the contestants manage to complete it, they'll get a key and check whether it can open the box or not.

The members have to escape by completing the missions and gaining the keys to open the box with the tickets for the bus to Seoul and they only have limited time.