Reach the museum to start the next mission
Get near the museum. To get inside, you will have to climb onto the roof. You will do that by flying over from the rooftop of the nearby gallery. To climb up, use farmer's disguise and water the lants by the wall.
In the first room, pick the green color swapper gun to fill the pistol, fire at the red button and cross the door. Reach the rooftop, where the only thing you have to do is destroy three fans in the center of the roof and rebuild them into a big one. Then, fly over to the museum.
Interior of the museum
In the museum, first walk towards the closed shop, where there is a lever. Mount in in the bottom-left part of the museum on the wall. Then, using the rope, release the racecar on display. Rebuild it into a dynamite dispenser where it crashed.
Use dynamite to blow up the silver block next to the railway engine and use the bricks to build a stove pipe. Now, destroy another object in the recess next to the railway. Build a small cart for the stove. Push it over and attach to it several bricks from another object in the recess. Push it over, collect the valve from the opened recess and mount it onto the cart. Then, give it a twist to reveal stairs to the upper floor.
It's down the slope now. At the upper floor, destroy two engines and rebuild them into a color swapper gun, then shoot green paint at the red switch. Take the crate with you and take it to the right, next to the oil pump. Build the missing parts of the pump and climb up. To the right of the ship, there is a construction side (21 000 bricks). There is a Big Super Brick to the right.
To find the second Super Brick, climb down. Next to the location where you have found the crate, there is a strange object in the barrel. Take it to the machine at the lower level, next to the locked gate. After you have put the object inside, you will receive a key to the gate. It is behind the gate that you find the second Big Super Brick.
After you have built the structure, walk over to the ship and climb onto the mast, using the ladder. Walk over to the right and jump into the room with lunar exhibition. Examine cues and drop the object you have found into the basket. Then, rebuild the crate into a teleporting device. Past the second glass pane of the exhibition, you have to use two green valves. Rotate them until the hand of the clock above stops in the green zone. Only after you do that, you can use the lever and leave this place.
Jump up and use the fan. Use the color swapper to obtain red and jump down. The button that you have to paint is to the right of the lunar exhibition, where you have found earlier the Super Brick. Walk over to the next section of the museum.
First, go to the left corner and destroy the brick on the grass, next to the guarding booth. Then, follow the footprints with the scanner. You will find a feather. Use it on the dinosaur in the right part of the museum. Then, climb across the broken glass pane into the guarding room. Take dynamite and use it to blow up the door to the next guarding building on the left. There, you will find a terminal thanks to which the glass panes to all the exhibitions on this floor will open.
You can find the first Big Super Brick at the leftmost exhibition of the floor, which presents prehistoric man. Destroy the objects there and build another figure. Use the terminal in front of the exhibition and use the action key to hit the spinning wheel to remove all of the gray elements and form a symmetrical shape. Once you do that, the brick to collect will appear in front of you.
Walk over to the neighboring exhibition with Robin Hood. Just like earlier, destroy the crate, build the terminal and use it. You have to fire the arrow at the target when it is close to the spot the figure is aiming at. Prove your good reflexes and the Super Brick is yours.
The final Super Brick is at the exhibition to the right side of the stairs, with the Native American. While you are using the terminal, the three figures on display spin at random. Your task is to keep activating the terminal until a figure takes the form presented in the picture behind it. When this happens, press the button to lock it in that position and do the same with the rest of the figures. All three have to match their respective pictures. Only then, will you receive the third brick.
Finally, go to the center of the stairs, where there is T. Rex's construction site (30 000 bricks). After you have built it, the mission will automatically end. Make sure that you have completed all of the activities in this location.