Primeval - Season 1 Episode 6 Future Foe

When the original Anomaly in the Forest of Dean reopens and a string of disappearances plague the area, Helen Cutter returns with a warning for Nick Cutter and the team about the deadly, elusive new predator the team are struggling to track: it is not a creature from the past, but from the future. Nick and Helen both want to go on an Anomaly containment mission into the past to stop the future from altering it, which ends in terrible consequences.