Adrenaline

For some reason, Blair felt a chill run down her spine, as though sensing an ominous presence nearby.

She whipped her head and searched all around the campsite. 'Where is this horrible sensation coming from!?' Her breath got caught in her throat as soon as she noticed a shadowy figure holding a weapon on the other side of the road. 

She gasped loud enough to alarm Cadmus. He turned to see where Blair was looking. 

Just like her, his face went pale, and in an instant, he grabbed her by the hand, shouting at everyone else as he started to make a dash for the woods.

"RUN, EVERYONE! RUN!" 

Completely taken aback, Hershey, Hartmut, Russell, and Irvin looked at Cadmus.