MrBeast introduces the challenge, starting with a $1 dirt hut. The secret room is found under a predictable trap door, leading to a small, hidden room. The room is rated 11.5 combined score due to its simplicity, emphasizing not to judge a book by its cover.

Next is a $100 castle with a vast interior. The secret room is accessed by a complex roller coaster ride that triggers a hidden door. Despite the elaborate entrance, the secret room itself is considered lacking, receiving a combined score of 18.5.

A $500 mountain secret base features a seemingly easy-to-find initial secret, but then reveals a hidden library with another secret door leading to a large, impressive bunker. This room recreates elements from a previous MrBeast bunker video. It scores 19.5, putting it in the lead.

The $1,000 pyramid requires activating three levers to open a path to the next layer. The secret room, found among diamonds, is deemed less secret due to its easy discovery. It receives a low combined score of 17.1 because the secret wasn't hard to find despite the beautiful exterior.

A $2,500 volcano island house contains a secret base inside the volcano with a 'Fastables' rocket. The island itself is shaped like the Beast logo. The clever and hard-to-find secret, along with the detailed build, earns it a high score of 24, taking the lead.

A $5,000 build reveals a secret villain base with an intricate hidden entry. This massive, hand-built base features mech robots and a master bedroom overlooking the evil operations. It also contains a 'secret room within a secret room' for armor. This build receives an impressive combined score of 25, putting it in first place.

A $10,000 underwater dragon base is visually stunning from the outside. However, its secret rooms are difficult to find and less interesting. Despite being a huge and majestic build, the secret rooms' lack of intrigue and difficulty in finding them results in a lower combined score of 21.5, showing that higher cost doesn't always mean better secret rooms.

The final build is a $25,000 space bunker with five secret rooms, each referencing a MrBeast video. Despite its impressive size and detail, including a 'space' environment, the judges feel it wasn't as innovative as the $5,000 build, resulting in a score of 20, confirming the $5,000 build as the winner of the extra $10,000.