Biohazard Crisis halts train G257, with Kyle Shaw, on The Capital-Meridian Line's elevated bridge, leaving four hundred survivors. Resources dwindling, human nature clashing, Luke Shepherd and Kyle Shaw establish order, cannot escape power struggles, theft, betrayal. Infection crisis breaks out inside train. Survivors decide to start train, head for safe zone. Facing evolved Mutated Infected, group becomes band of brothers, holding on in apocalypse, searching for hope of civilization's rebirth.