This requires a Adept or Master Builder, Time Warp power, 500 energy, and the Purple Masked Master builder to be sitting in the area. To the right of the blocking totem are two small areas that look like building supplies. To convert the purple mask master builder, beat him or her at a building contest. The purple mask master is very fast. The purple mask master also tends to wander, so you cannot do the challenge until he or she is sitting below the challenge area. Bring your Master Builder to the area. Use the Time Warp powers on him or her, and they will speed up. Drop the builder immediately on the left pile of supplies, and he or she will quickly build an object. If you finish first, the purple mask will convert to your tribe. The necklace piece will actually drop near the statue, near where the other three pieces of the necklace are found. Drop a child on the piece and they will bring it to the rest of them and assemble the necklace.