Want to know where Primeval picks up the story after the events of Series 3? Then read on for a complete overview. Note that there are obviously spoilers!

One year after the death of Johnson and the disappearance of three key ARC personnel, the government lost faith in Lester’s (Ben Miller) abilities to run such a dangerous and expensive operation on his own. They placed the ARC in the hands of a public/private partnership, part-owned by the government, and partly by entrepreneurial scientist Philip Burton (Alexander Siddig). The ARC now operates from the industrial complex which houses Philip’s scientific empire; an estate of buildings with all the hustle and bustle of a thriving scientific community. As with any public/private partnership, there’s tension over who’s really in charge; Lester still runs the day-to-day operation but begrudgingly, he realizes that Philip will want involvement in the operation when it suits him.

Following Connor (Andrew-Lee Potts), Abby (Hannah Spearritt) and Danny’s (Jason Flemyng) departure, the ARC found new recruits to take their place: Matt (Ciarán McMenamin), new field leader, now handles the incursions. He’s more than just an ex-soldier; he’s a zoologist, with an uncanny ability to understand animals. A private man, Matt carefully guards the secrets of his past – and the real reason he has joined the ARC team. Unconventional Jess (Ruth Kearney) now runs operations from the ARC Control Centre – highly efficient and organized, her work ethic is second to none, though she is human enough to nurse an unrequited crush on Captain Becker (Ben Mansfield). Becker reigned from the military when the ARC was destroyed, and has lived with a sense of responsibility for the original team going missing. He now works as a private soldier for the ARC. They come complete with new uniforms, and most importantly to Matt, new EMDs (electro-muscular disruption devices); taser guns which avoid killing the creatures.

During the year they spent stranded in the Cretaceous, Connor and Abby eked out an existence by eating roots and grubs and learning when to run fast from the creatures that threaten their lives. It’s an experience that has brought them closer together, in every sense. But their time there has taken its toll…both emotionally and physically. Abby, always the most practical one of the two, has adapted to her new surroundings slightly better than Connor, who was always happier around technological comforts than out in the wild.

Danny, the only outstanding member of the original team, returns, and his revelations will have a profound effect on the ARC and its team. He has struggled through life in the Rift Valley, and has fought to find a way back after discovering a secret the team needs to know. His return is greeted with shock and happiness, but his revelation soon throws some members of the team into an even more desperate situation.

Primeval returns January 2011 on ITV1.