If you mean the 3 sync plates at the begging then once you capture them (turn them white) you have to hold them for an amount of time while a spire forms which will open the door to the next area. You will be attacked by waves of enemies, especially Minotaur's who will try to recapture the plates and stop the spire forming. All three plates have to be in your control (white) for the spire to keep forming.