I found out earlier today that
five webisodes were made for "Primeval" to be watched before the start of season four. And not five "oh, look what we did over summer vacation! :-D" type webisodes, but Big. Important. Character. Development. type webisodes.
Which, given the way season three finished, and season four started, makes sense. I just wish I'd known about them before getting through most of season four and going "WTF?" for the first couple episodes, then just rolling with it for the rest so far.
Guess what I'm going to go watch now. :-P