4 0 1Actions Report Solution Once you unlock the Grapple find a quiet corner with a lone zombie (i had one left in a Quarantine Zone) and throw the poor bugger around until this unlocks. If it bursts, just find another and continue.Showing only comment. Great solution :-) This worked for me although I did it with a group of three zombies. Just make sure you watch your back if you do it with any more than one!Posted by adonbilivit88 on 13 Jun 15 at 13:35