And so, because of that, this is known as the repolarization period. So it tries to repolarize and return that voltage to its resting membrane potential of about negative 70 millivolts. But let's see what happens. Notice that it actually drops below the negative 70 millivolts value. And that's because many of these voltage gated potassium ions actually open. And so we have this outflux of these potassium ions out of the cell, and that causes a hyperpolarization period.