is that the 1 that a flood dude has on his hands if it is you have to start that level from the second check point (right before you fight the flood) at this time you supossed to go to the crash site where the flood is when your are heading back towards the buildings keep your eyes fucused on the top of the first building on the right and where a cable wire is before the checkpoint youll see a flood guy jump to the other building you have to shot him before he jumps or most likely some where betwwen about to jump and is hard some times to catch that dude so it might take you several times so try to revert to the last check point Before they give you the other check point so if you shot him too soon he will drop the ball on top of the building and you dont want that cuz u cant get up there and if you shot too late it would land in a random place that is out of limits?? well i guess youll know wat im talking about once you see it

lol ok the catch skull you get it at the storm and so ok right or as soon as you get out of the building there is gona be a battle going on and stuff and they tell you to take out the air attack tank but DONT if you destroy it before you get the skull the skull wil not be there thats the reason you didnt see it because you probably destroyed the tank well now you know not to destroy it its easyer if you do it on co-op but if you are solo just try to get some marrines to help you out i sugest to take the anoying ghost and then just park the hog on that round thing and get up wit a extra bost from a nade but remember DONT DESTAROY THE TANK OR THE SKULL WILL NOT BE THERE hope this helped

IT IS LOCATED AT THE STORM!!!!!!!!!!!!!!!!!!

Okay, Dude. When you enter a giant field with the first Anti-Air Wraith, and you see a
regular Wraith being dropped off, DO NOT DESTROY WRAITH AT ALL COSTS!!! IF YOU DO, THE
SKULL DISAPPEARS!!! My advice is, get all the ghosts that still work that you can (for
best results, three is the best.) Also, MAKE SURE YOU HAVE A WARTHOG THAT STILL WORKS!!!!
If you have the following AND have not destroyed the normal Wraith, then go to the
circular building near where you destroyed the Anti-Air Wraith. If you look closely
enough, in addition to the building, there is also a section of circular wall that
surrounds the back. What you want to do is drive the three ghosts in the space between the
building and the wall (if you find it hard to do, using the speed thrust on the ghosts
will make it much easier). After this, drive the warthog up against the ghosts and jump up
on top ofthe propped up warthog. you should be easily able to jump on the top and claim
the skull.

or you can just grenade jump