How to get a free Zombie Blood Every Round in the Call of Duty Black Ops 2 zombies map, Origins.

To do this you will first need an ice Staff or Ultimate Ice staff. Next you will need to extinguish 3 flaming carts around the excavation site. If you do not do this quick enough the carts will light back up. Once you ahve extingushed all 3 head inside to the excavation site anf to the right of the Pack a Punch machine you will find the Free Zombie Blood Drop. This can be done once per Round.
The cart locations include:
1. In a footprint near Generator 4.
2. At the entrance to Generator 5.
3. Directly beside the excavation site sign.