Harry's Head
As long as Devin could hold them at bay, Kara went to open the door to where Harry had been killed. She would open it just a crack at first, to get a look in and ensure it was unoccupied.
If so, she opened it all the way, checked again for emptiness, including spiders on the ceiling, then went in to recover Harry's head if he was still there. Preston would be at the doorway, ready to shut the door if it needed to be shut in a hurry.
If occupied, what she did depended on what was inside.