Season five continues the story from season four and more than makes up for that season's lack of budget/creatures. Genius Connor Temple (Andrew Lee Potts) continues to work for Philip Burton (Alexander Siddig of STAR TREK: DEEP SPACE NINE) on a secret project. It turns out that this is to create a giant time anomaly that will create a source of free power for the world. Yet it's revealed that Burton is a colleague of the late Helen Cutter, who was the Ark's arch-enemy the first three seasons of the show. So, can he be trusted?
Matt Anderson, the newest member of the group, reveals to Abby Maitland (Connor's girlfriend) that he's from far in the future and that he's on a mission to stop Philip experiment. And he shows her that Connor is responsible for the future earth being a barren wasteland. So it's basically Conor/Burton vs. Anderson/Maitland for this season.
Matt also manages to rescue his love-interest, Emily Merchant, from the past to which she has returned in the previous season. He discovers that her husband commits her to an insane asylum because of her unlikely story of traveling to the future.
Monsters this season include giant carnivorous beetles, a primitive crocodilian, raptors, a giant mososaur that attacks the crew aboard a submarine, and a return of those weird humanoid bat-creatures that live in Matt's future.
I'd say this last season is as gripping as the first two. Best of all, it explains what the anomalies are and why they are a necessary part of nature. I'm not sure if there are going to be any more seasons of this show but the last episode stands as a good conclusion to the series.