Challenge - Do not release any locked up zombies<br /><br />0:00:00 - Normal the stairs.<br />0:00:05 - Pause and Explode the 1st zombie.<br />0:00:06 - Evolution 9 zombies to tanks.<br />0:00:10 - Sacrifice the next zombies to recharge DNA at least 104.<br />0:00:17 - After the machine gunner passes the 3rd column of the bridge, let all tanks run to the machine gunner.<br />0:00:22 - Spitting to Michelle from the 1st tank.<br />0:00:23 - Spitting to the machine gunner from the 2nd tank.