A fanatical group of xenophobes attempt to rid Earth of all non-humans and end all extraterrestrial relations.
4-01: Storm Front, Part I
Trapped in Earth during World War II, Enterprise investigates dramatic changes in the timeline as a result of the Temporal Cold War.
4-07: The Forge
After a terrorist attack on Vulcan kills Admiral Forest, an investigation leads Enterprise to believe that an secluded group called the Syrrannites is responsible.
4-05: Cold Station 12
The Augments attempt to steal the remaining genetically-engineered embryos from Cold Station 12.