Haunting magical act horrifies Howie Mandel on 'AGT: All-Stars': 'I was stabbed in the back'

Another week of "AGT: All-Stars" auditions evoked feelings of awe, confusion and fear.

In the fourth round of tryouts for NBC's super-sized competition (Mondays, 8 EST/PST), another group of acts attempted to impress judges Simon Cowell, Heidi Klum and Howie Mandel. It was Klum alone who had access to the Golden Buzzer and the power to send an act straight to the finals. A second spot in the finals would be decided by a voting panel of "superfans" viewing the auditions and deciding on their favorite. The other acts, unfortunately, would face elimination once more.

Here's how the evening played out:

The Golden Buzzer act: Teenage magician Aidan McCann

Thirteen-year-old Aidan McCann worked his magic on Klum, moving her to hit the Golden Buzzer. The Irish illusionist said he picked up the interest at age 5 and competed on "Britain's Got Talent" in 2020.

On Monday, he sought assistance from show host Terry Crews, who selected a superhero name from McCann's deck that was not revealed. A blindfolded McCann then instructed the judges to color in a drawing of a superhero. Cowell colored the cape green. Klum chose pink for the hero's shirt. Mandel selected orange for the hero's shorts and blue for his tights.

McCann said he predicted each move the judges and host would make.

To prove his point, he removed his tear-away suit to reveal a hero's outfit that matched the judge's artwork and Crews' pick of a superhero name. Titan Jr. was written across McCann's chest. Crews, tearing away his own suit, revealed he had a superhero suit matching McCann's with Titan written on his chest.

"Wow," Cowell said repeatedly in astonishment. "Thank God you're here! That was unbelievable!"

"I love the magic, but really it is you who is the magic," Klum said. "You really are. I think you're such a little star. You sparkle, and I don't know. What's my head saying? What?" she said reaching for the buzzer.

All about the backwash: Human Fountains return

What's a little spit between friends? The novel act Human Fountains, who competed in 2018, returned with their water bottles in hand. As the name suggests, the trio of men (previously a foursome) sip water and then project it like a fountain would.

The group performed a patriotic routine to "God Bless America" as they spit water into each other's mouths. In another stomach-churning moment, one group member took a hot dog from his mouth, placed a bun inside, and then passed it to another member who spat mustard onto it. The lucky third member ate it.

Shortly thereafter, Cowell his buzzer, giving the group an "X." Crews called the act "incredible," and Klum said she was excited by the group's return.

"We're definitely missing the fourth person, in my opinion," Cowell said over the audience's boos. "And I think the spitting was higher last time, from memory."

Sacred Riana unnerves Howie Mandel

A haunting magic act proved too much for Mandel to handle. Sacred Riana, a contestant on "AGT" in 2018, pulled the judge to the stage to help him with her eerie act and directed him to sit in a chair.

Standing at a nearby table, she drove a knife into its surface causing Mandel to jump. "I feel like I got stabbed in the back," he said.

Later Mandel said he heard a voice saying Howie, though no one else appeared to hear it. "I swear to you," he told the audience.

When Mandel returned to the judge's table he found a note that read, "I'm coming for you, Howie!!!" Then the stage went black and Riana disappeared.

"Are we at the end of the act?" Klum asked. "Is everyone as confused as I am?"

"Well apparently somebody's coming for me," a shaken Mandel said. "So I would like to get the judging out of the way so that I can leave."

"I'm really, legitimately, I'm not kidding," he added. "I'm telling you that I'm terrified."

"Terrified of what?" Cowell asked.

"Read the note!" Mandel shot back. "I was poked in the back, I was stabbed in the back. He knows my name, and he's coming for me."

With that, the judges continued on with the show.

Who did the superfans vote through to the finals?

Which one of the remaining acts would be sent through to the finals thanks to a group of "AGT" enthusiasts? Crews revealed the voters' Top 3 to be: married aerialists Power Duo, the Ndlovu Youth Choir and dancer Darius Mabda.

The young dancer received third place, and the choir second, meaning the superfans championed the moving Power Duo to the finals.

Catch up on the season so far:

• ‘I would never guess that’: ‘AGT: All-Stars’ premiere's Golden Buzzer act, shocking elimination

• 'AGT: All-Stars' judge Simon Cowell 'mesmerized' by Victória Bueno, teen ballerina with no arms: Watch

• 'Is he alive?': The outrageous 'AGT: All-Stars' act that Simon Cowell couldn't bear to watch

This article originally appeared on USA TODAY: 'AGT: All-Stars' recap: Howie Mandel horrified by Sacred Riana act