The novel explores Bella's compromise between her love for Edward and her friendship with shape-shifter Jacob Black, along with her dilemma of leaving her mortality behind in a terrorized atmosphere, a result of mysterious vampire attacks in Seattle.

The story begins with Seattle being plagued by a string of unsolved murders, which Edward Cullen suspects is caused by a newborn vampire with an uncontrollable thirst for human blood.

The Cullens join forces with the wolf pack to combat this threat, after their longtime allies, the Denali Coven, refuse to help them.

[5] Meyer stated that the events of Eclipse are centered on Bella's choice to become a vampire and fully comprehending the price she has to pay to undergo the transformation, which she didn't understand in Twilight and New Moon.

"[4] In August 2009, The Telegraph reported that HarperCollins' Wuthering Heights edition—which has a "gothic" cover similar to the Twilight covers—has sold more than 10,000 copies since May of that year, more than twice as many as the traditional Penguin Classics edition, and topped the newspaper's classic books chart for the first time due to Meyer referencing the novel.

Although it was supposed to be disclosed to the public in May 2007 at the Eclipse Prom, Barnes & Noble and Meyer's official website premiered the newly released cover in March 2007, along with a preview summary of the book's plot.

[7] The broken ribbon represents choice, as in the book Bella must choose between her love for the vampire Edward Cullen and her friendship with the werewolf Jacob Black.

Meyer also stated that the ribbon represents the idea that Bella is unable to completely break away from her human life.

[13] On July 25, an incident similar to the early release of the seventh Harry Potter book occurred with shipments of Eclipse.

[21] It also ranked #1 on Publishers Weekly's list of "Bestselling Hardcover Backlist Children's Books" in 2008 with over 4.5 million copies sold.

Anne Rouyer of School Library Journal gave the novel a positive review and said that, "Meyer knows what her fans want: thrills, chills, and a lot of romance, and she delivers on all counts."

Rouyer also thought that as in the two previous installments, "it is Meyer's effective and intense portrayal of first love in all its urgency, passion, and confusion that drives the story along with the supernatural elements coming in a close second", and said that the "injection of heightened sexual tension and sensuality that hasn't been present in the series before" contributed well to the emotional atmosphere of the novel.

However, she found that the werewolves' and vampires' histories slowed the book's pace and called the newborn army's story a "convoluted add-in", while noting that they "contribute in some way to Bella's epiphanies about her future.

"[24] Publishers Weekly wrote, "The legions of readers who are hooked on the romantic struggles of Bella and the vampire Edward will ecstatically devour this third installment of the story", while noting that, "it's unlikely to win over any newcomers.

Fans of Bella's angst-drenched love triangle will gobble this entry up, and the open-ended conclusion paves the way for Jake's story to come.

She found "the first several chapters stifled by issues of jealousy which are slow to develop", and said "Meyer's new sources of conflict feel heavy-handed at some points and over-the-top at others."

Despite praising Meyer for uncannily understanding and writing the workings of the teenage mind, she noted that Bella is slow on the uptake of some obvious aspects of the plot.

[27] Novelist Elizabeth Hand wrote a negative review of the book for The Washington Post, calling it a "disappointment" and criticizing it for "never delivering an epic werewolf-bloodsucker smackdown", as well as for Bella remaining "an insufferable bore".