Joey thought of one possibility: schizophrenia. This usually appeared in the early stages of contamination.
He watched the deranged Anderson in silence and waited.
A long time passed, but Anderson kept giggling mindlessly. After watching for a while, Joey lost interest and decided to leave him alone for now and study the images carved into the stone wall.
The first image looked like a magical ritual, with a group of people kneeling in worship around a sphere.
He turned to glance at the fireball overhead.
The thing in the mural was probably that very object.
The second image showed countless tentacles sprouting from the sphere on the altar and dragging all the worshippers inside it.
Wait. Eight people? Joey noticed that there were eight worshippers. From their simple distinguishing features, he could tell there were three women and five men.
That matched his group exactly, if he excluded himself.
Could there be some connection? With that thought, he glanced back at Anderson.
That glance sent his expression changing dramatically when he saw what Anderson was doing.
"Don't move!" There was no time to think. He could only watch as Anderson hurled himself headfirst at the red sphere, heedless of his life.
A living man was reduced to a pile of ashes by the red sphere's searing heat, right before his eyes.
At the very last moment, all he managed to hear was Anderson's agonized roar: "Annie Bullock!"
At the same time, the entire underground space began to shake. Countless rocks fell from overhead, followed by torrents of water surging in from every direction.
Joey had not even figured out what had happened, why Anderson had suddenly gone mad, or why he had shouted Annie's name at the end.
"Fuck! Anderson, you fucking-"
Before he could finish cursing, water flooded his