Halo 2 HI BEN – Achievement Guide
Complete Skull and Terminal CHECKLIST(Halo 1-4 / Google Docs)
Turn on the Sputnik Skull for this jump.
Right at the beginning of Regret you will fight some enemies. Kill them and walk outside. If you look right, you see a big gap. Grenade Jump over it and go into the room to your right. On the ceiling in a corner you will see the hidden message Hi Ben. You will have to zoom in twice and switch to classic mode to see it.