[quote][b]Posted by:[/b] path1k you folks remember the part in two betrayals where a group of infectious forms are waiting outside the door for you right? when the door opened they didn't swarm towards me like they usually did in HALO Combat Evolved but instead they quickly flew into the air and exploded. so i reverted to last checkpoint and opened the door without stepping outside, shot a few rounds above them, they remained statue still, threw a grenade at them which didn't do anything when it exploded moved towards them and again: immediately rise towards the ceiling and explode strange, so i continued to kick ass with bandana, grunt funeral, boom and pinata[/quote] It's the Grunt Funeral Skull. The Grunt explodes and kills the Infection forms. But the Infection forms are not supposed to be killed at that point, so they just freeze.