When i play halo 3 co.op with my brother on normal, why doesn't the

[Gustavo R]

skull appear on seirra117? I go up on the bridge and the skull doesn't appear at the far end, I have the mode on normal, and tried it on heroic, but still nothing.. Why?

 

[Goldenbug7 T\.I.]

are you sure you're going to the right place? you have to go straight accross the bridge, climb the wall with a grenade jump or grav lift or portable shield thing, then follow the ledge around as far as you can until you are just accross the river from where you entered the area.

 

[Kyle C]

Common problem, the only thing I can think of is that you may need to rescue SGT. Jonson first. aside from that, start from the VERY beginning or the skull will not appear.