The Series 4 material launches roughly a year after Abby, Connor, and Danny went back to stop Helen, and got stranded in the past. There's going to be a new team taking over the ARC, which is now under new management. Fear not, however, for Abby Maitland, Connor Temple, James Lester, and Captain Becker return in the new series, joined by some new cast members.
However, some folks may not know that ITV has done up a series of short, 3+ minute long webisodes that introduce the new characters, and put some perspective on what's been going on the last year or so. While we Canadians can't watch these webisodes on ITV, they have been posted up to YouTube, so here are the links to them:
Primeval Webisode 1
Primeval Webisode 2
Primeval Webisode 3
Primeval Webisode 4
Primeval Webisode 5
Also note that Space will be showing the Series 3, Episode 10 cliffhanger immediately before the start of the Series 4 material, so you may want to check that out as well. After all, Primeval's been off our television screens for lo these many 18 months or so!
Make mine PRIMEVAL!!! :)