“Adrift” is episode one of season four of Stargate: Atlantis.
In the previous episode, “First Strike”, the previous season‘s finale, the city of Atlantis had lifted off from its planet and entered hyperspace.
Unfortunately, it ran out of power and exited hyperspace before it reached its destination, leaving it stranded in the middle of nowhere and with very little power to stay alive. This leaves everyone rushing about trying to fix the city before power runs out and save Dr. Weir’s life.
Colonel Carter plays a part, although not a significant one, and McKay is pretty amusing in this episode, as every time he gets positive, something else bad happens.
The problem isn’t wrapped up by the end though, the situation is still ongoing and the story continues in the next episode “Lifeline”. Fortunately, no major characters were killed off – yet.