The much-anticipated premiere of “Under the Dome” scored well for CBS. The Monday night premiere was the highest-rated show for CBS this summer and trailed only “Revolution” for the year’s highest-rated drama premiere.

“Under the Dome” earned a 3.2 rating, 13.1 million viewers, among the coveted 18-49 demographic, notes the Hollywood Reporter. The 3.1 rating ties the “Under the Dome” premiere with Fox’s “The Following” but it fell short of the 4.1 rating for the premiere of “Revolution” in September. The ratings are also among CBS’ best for a summer debut, with THR noting only 2000’s debut of “Big Brother” gained more viewers than “Under the Dome.”

Strong word of mouth and critical reception could help the show, an adaptation of the Stephen King book of the same name, maintain the high ratings. On Metacritic, “Under the Dome” has a score of 72 out of 100, 28 positive with six mixed and one negative review from critics.

“Under the Dome” entertained viewers but left them with plenty of questions. As the town of Chester’s Mill becomes enclosed under a dome that mysteriously appeared, the premiere provided few answers about the town or its inhabitants.

Brian K. Vaughan, the show’s producer and creator of the comic series “Y: The Last Man,” discussed some of the biggest questions left unanswered by the premiere with THR. He said the producers, who include Neal Baer (“ER” and “Law and Order: Special Victims Unit”) and King, have an ending in mind, complete with a final scene. But the mystery of the dome will remain unsolved for the duration of the series.

Other mysteries, such as the propane conspiracy involving James “Big Jim” Rennie, the town’s selectman, Junior Rennie’s violent turn, who Barbie is and the mysterious seizures, will be explained rather quickly. Vaughan promises answers will come often during the first season of “Under the Dome” but he hopes the show will have a multi-season run.