So our potassium rushes to the outside, and that causes the inside of the cell to basically become more negative, and eventually it returns to the resting membrane potential. So as the calcium voltage gated channels begin to close, the influx of potassium exceeds the influx of calcium. So the movement of potassium to the outside exceeds the movement of calcium to the inside, and that basically causes the opening of even more of these voltage gated potassium channels shown in green. And that causes the increase in the rate of movement of our potassium to the outside. And that causes the inside of the cell to become more negative because we have the movement of positive charge to the outside. And that basically continues until we reach our resting membrane potential, until we reach our phase number four, this brown section.