Under The Dome cancelled after season 3: Series finale episode synopsis and air date revealed

After a lot of speculation, CBS has officially announced that Under The Dome will be cancelled after its 3rd season and the final episode will air on Thursday 10 September. The network also announced that the finale will see the dome at Chester's Mill coming down and revealing all its secrets.

CBS Entertainment chairman Nina Tassler said, "Two years ago, Under the Dome broke new ground in the summer and became an instant hit on CBS, as well as with viewers around the world.

"Dome's event storytelling and multi-platform business model paved the way for more original summer programming with the successful rollouts of Extant and Zoo. We're excited to present the final chapter in Chester's Mill as the story comes full circle, with the Dome coming down as dramatically as it went up."

Based on the 2009 Stephen King sci-fi novel of the same name, Under The Dome focuses on the trials of a small town that is suddenly cut off from the rest of the world beneath a massive, transparent dome. The show premiered with strong ratings, but with the third season, the show's rating hit a series low.

Episode 13 which will serve as the series finale is titled, The Enemy Within, where Resistance makes its last stand against Kinship and its new queen.

The official synopsis reads as follows:

As the Dome in Chester's Mill comes down, the Resistance makes a final attempt to protect the outside world from the infected townspeople in the Kinship and their new queen, on the third season finale of Under The Dome.

Previously, executive producer Tim Schlattmann said the townsfolk discover the secrets and purpose of the dome and its origins by the end of season 3.

Schlattmann revealed, "We are answering all the questions ... by the end of the season," and added, "We threw a lot of stuff at you in the first two hours. By the end of the season, you will know everything. I usually don't use this language ... but things are gonna get bananas."