Mitt Romney's Mormon faith, long considered a potential issue in his presidential campaign, came under scrutiny this week when Vanity Fair published excerpts from an upcoming book that delves into Mitt's history as a lay leader in the church. The Real Romney, authored by Boston Globe reporters Michael Kranish and Scott Helman, suggests that Mitt once threatened a single mother with excommunication if she didn't give her soon-to-be-born baby up for adoption — an account the Republican frontrunner denies. Here, a brief guide to this unsettling story:

What does the book claim?
In the early 1980s, Romney was serving as bishop of a Mormon congregation near Boston. Peggie Hayes, a 23-year-old divorced single mother, became pregnant with her second child. Knowing she needed help, Romney arranged for Hayes to get odd jobs from other church members. But as bishop, Romney also bore the responsibility of briefing Hayes on church doctrine. As quoted in the book, she claims he showed up at her apartment and encouraged her to give her baby to the church's adoption agency. According to Hayes, Romney said: "This is what the church wants you to do, and if you don't, then you could be excommunicated."

Excommunication is a big deal, right?
It sure is. "This is not playing around," Hayes said. "This is not like, 'You don't get to take Communion.' This is like, 'You will not be saved. You will never see the face of God.'"

Does Hayes have an ax to grind?
That's unclear. She does have some nice things to say about Romney. But in the end, Hayes had the baby — and left the church shortly afterward. When her child needed a risky surgery, Hayes says she called Romney for a blessing, and he dispatched two church members who Hayes didn't know. "I needed him," Hayes said. "It was very significant that he didn't come."

Did this all really happen?
Romney says it didn't. And as bishop of Hayes' ward, Romney didn't have the power to kick anyone out of the church. That power belongs to a council of church officials. The church does encourage adoption in cases where "a successful marriage is unlikely," the book says. But keeping a child to raise in a single-parent home isn't considered a sin grave enough to warrant getting booted from the church, which the faithful believe cuts off the path to heaven.

Will the story affect Romney's campaign?
It probably won't help. Romney has been careful to avoid saying or doing anything that could stir up the already pervasive uneasiness about Mormonism in the general population, particularly among evangelical Christians who make up an important part of the GOP's base. And it won't help him with skeptical women voters, either, says Eesha Pandit at Feministing. "First, he's not sure about contraception. And now this. Regardless of whether this is fully accurate... if Romney makes it to the general election, he's going to have to do some serious work to convince any women at all to vote for him."

Sources: Buzzfeed, Feministing, Jezebel, Vanity Fair