David looked like he had seen a ghost, and Brennan angrily retracted that metaphor in his head. David and his obsession with ghosts has given him more than enough stress, and he was getting sick of it. Honestly, he wasn't sure if it went all the way down to jealousy on his part that David could somehow manage to do things that he loved even after the end of the world, not that Brennan would ever acknowledge that feeling. He didn't believe in half of the shit that David rambled on about, ghosts and all his theories and that stupid thing he always carried around, the name of which he had forgotten. It was some sort of "ghost tracker" or some bullshit, and he knew the guy always carried the damn thing around, and was pretty sure he saw him trying to hide it as he walked up. And if Brennan wasn't concerned with whatever had been in the water, he might have let himself go on another tirade about the device and/or toss the thing into the water where the fucking swimmers could have it for all he cared.
He ignored David at first, looking over his shoulder at the pier, checking if there was anything coming up out of the water or something moving that couldn't be attributed to the waves crashing up in the supports, his grip on his knife tight enough that his hand was almost trembling. He ended up not seeing anything, David's screaming probably scaring it off, but he kept checking every once and a while. Tucking the knife away for the time being, he decided to address David, a choice he might come to regret within the next few minutes.
"What did you think you were going to find in the water?" He checked the surf again. God he hated how these infected made him so paranoid. He was afraid that more swimmers might be heading this way. They used to be intermittent and few in number, but it was only a matter of time before a larger group headed for the island. "How many did you see?" He asked, hoping that David had actually gotten frightened by a swimmer and not a tuna or something. He was being shockingly lenient with the other man today. It just might be a cold day in Hell.