You need to go to the Hangar Room in Truth and Reconciliation the first time you go into the room this is when after you board the ship and you go through a few rooms then you go to the Hangar Room and now you need to wait for the 2 hunters to come and you should go to the door that they come out of because you will need to jump through the door quickly because it will close and it will not open again.

You need to go inside the door the 2 hunters come out of this door is only opened after the 2 hunters leave the room and it will not open again you might need to wait outside this door for it to open so you can get in quickly and inside will be the skull the skull is inside this room.

You now have collected the skull and thank you for reading my guide.