“Once in a Lifetime” is episode twelve of season one of Eureka and the season finale.
Stark is overseeing a test on the mysterious artefact that has been mentioned several times. Things do not go well, and there appears to be a significant event. After the event, Carter is in bed in his bunker with a, very pregnant, Allison.
We are seeing the future – 2010 at that time, which is revealed shortly at the class graduation of the Tesla School. There are some interesting relationships and changes.
Then a charcoal briquette of a body mysteriously appears fused to a wall in Section 5. The next mysterious appearance is that of Carter’s old car – which has apparently come from over three years ago.
There’s another temporal anomaly, like the one in “Pilot”. Walter, who caused the first one, is now a teenager, and under house arrest. The charcoal briquette turns out to be Kim, seen in “Before I Forget” – but she’s also alive, and she’s the one who identified the body. The dead Kim died four years ago.
This is bad, as the two different timelines are now colliding, and the anomalies are getting worse.