Once the first zombie attacked, the rest followed.  It was an inexorable tide, a domino effect.  Jess took deep breaths and reminded herself it wasn’t real, all a simulation.  She touched the bridge of her goggles, and waited for the zombies to get in range.  The team rushed past her, and the zombies were right behind.  She reached down and pulled the line at her feet taut.  The tripwire was lined with improvised weaponry that bit into the zombie’s flesh and ripped through them at the ankles.  The trap bought them five minutes before the undead found its way around.