'The Voice' Season 24 Spoilers: 'Drastic' Rule Change Sees Eliminated Contestants Back On Show

John Legend, one of the coaches in the Season 24 of "The Voice" broke down after one performance during the Knockout Rounds, which may have affected the drastic rule change that's never been done in all 23 previous seasons of the talent reality series.

The 44-year-old "All of Me" singer, as well as Gwen Stefani, were moved to tears after a contestant from Niall Horan's team gave a powerful performance of Jason Mraz's "I Won't Give Up." Legend told Lennon VanderDoes that he thought he was the team's underdog and said, "I just felt you being fully yourself, and it felt so moving to me."

"I don't know why I keep crying. I can't stop," he continued. Reba McEntire, their fellow coach, told VanderDoes, "Lennon, I hope you realize that the biggest compliment another artist could give you is just to sit there and cry because you touched John to his core."

Meanwhile, VanderDoes' coach Niall said, "These two crying says it all."

Despite moving Legend and Stefani to tears with the performance, Niall picked Alexa Wildish, who performed Cher's "Believe," as the winner of the Knockouts. She bested VanderDoes and contestant Julia Roome, who performed Sia's "Unstoppable."

Wildish's voice and performance were described by "The Voice" as "magical" and "one in a million" when her performance video was uploaded on its YouTube channel. 

"The Voice" Season 4's latest episode ended with a cliffhanger, showing the host Carson Daly gathering backstage with the coaches and telling them, "Something happened this particular season. The artists are getting better and better. In the Blinds, we had more four-chair turns than we ever had."

"The Knockouts... we've never seen anything like it! So, we've changed the rules. We've had to do something rather drastic - something that's never been done in all [23 previous] seasons on 'The Voice,'" he explained.

It then showed the coaches FaceTiming four previously eliminated mystery contestants to invite them back to the competition.

While the contestants' faces and identities were hidden, their voices gave the viewers a hunch that VanderDoes was one of them.

"The Voice" airs every Monday at 8 p.m. PT/ET and Tuesday at 9 p.m. PT/ET on NBC.