La serie comienza con la aparición de criaturas prehistóricas en diferentes partes del mundo, desde enormes tiburones hasta feroces dinosaurios. Estos animales, que se creían extintos desde hace millones de años, comienzan a aparecer en el presente, poniendo en peligro la vida de las personas. Un equipo de científicos y cazadores, liderado por el Dr. Nick Cutter (interpretado por Matthew Macfadyen), se da cuenta de que estos animales están viajando a través del tiempo desde la era prehistórica.

The series Primeval follows a dedicated team of scientists and government officials tasked with investigating "Anomalies"—mysterious ruptures in space-time that act as gateways between the present day and Earth’s prehistoric past or terrifying future. Led initially by evolutionary biologist Nick Cutter, the Anomaly Research Centre (ARC) must contain lethal creatures while grappling with the ethical and scientific consequences of a changing timeline.

In the first season finale, Cutter discovers that his wife, Helen Cutter —who had been missing for years and presumed dead—is actually alive and has been traveling through the anomalies for years. Helen has become corrupted by her travels and seeks to manipulate time.

The series centers around anomalies appearing across the globe, through which prehistoric creatures from various eras emerge into the present. These include everything from dinosaurs and ancient reptiles to more exotic, never-before-seen creatures. A team of scientists, led by Dr. Rick Mitchell (Andrew Lee Potts) and his partner, Paterson (Geraldine James), works alongside zoologist Zoe Heriot (Lindsay Duncan) and later on, Dr. Jonas Walker (Dominic Coleman), among others, to track and contain these creatures.

Beyond just dinosaurs, the team faces giant insects, marine reptiles, and terrifying "Future Predators". The Emotional Core:

Además, existe Primeval: New World (2012), una spin-off canadiense de una sola temporada, que aunque no es tan querida como la original, es un complemento interesante para los fans del "Dual Work".