Power runs up the riser from the base and is tied into the appropriate level via a jumper. The cube is divided into 8 sections since it is really just a remapping of 8x8 rainboduino to 4x4x4. You only connect one jumper on each riser and only one to each level on each side for a total of 8 jumpers soldered. If you connect more than one on a specific riser then all the LEDs on each of those levels (on that side) will light up at the same time.