Following directly on from the the events of Part 3, we find that the mysterious scientist who popped up at the end of that film, who is secretly working for the unscrupulous Wexel Hall Pharmaceuticals, has been conducting his own experiments on the blood orchids and has been doing his own experiments on some baby anacondas at some remote cabin in the woods.
Needless to say, his test subjects subsequently break out and eat him, then go on the rampage in the Romanian countryside. Much to the chagrin of Dr Hayes (Crystal Allen), who's returned to the area with a couple of cops to show them the carnage that took place in the last film.
The snakes then proceed to chow down on the officers, a group of archeology students who are conducting a dig nearby and a group of mercenaries, who the company boss had hired to find out what had happened to the rogue scientist he'd paid to do these illicit experiments.
As with the previous film, it's exactly what you'd expect from a low budget, made for TV sequel. Featuring more hammy acting and duff CGI giant snakes. It's still quite good fun though, it was also good to see John Rhys-Davis and Crystal Allen reprising their roles.
If you enjoyed the previous films, you should enjoy this. Just don't expect any oscar winning material here.