The Masked Singer reveals Bluebell as Natalie Imbruglia

Warning: This contains spoilers for The Masked Singer season 12, episode 6, "'60s Night."

The Masked Singer got a groovy makeover on Wednesday thanks to '60s Night.

In addition to all of the flower-power goodness and big, big hair, the themed episode also served as the finale for the remaining Group B contestants: Goo, Bluebell, and Wasp.

Naturally, the proceedings kicked off with a performance of a hit from the quintessentially '60s band, the Beach Boys. Wasp, Bluebell, and Goo all got to partake in the "Fun, Fun, Fun" as a result.

For most of the episode, it was business as usual. The finalists each had to perform a '60s hit, which for Goo meant "House of the Rising Sun" by the Animals, while Bluebell sang "Do You Love Me" by the Contours and Wasp did "Ain't No Way" by Aretha Franklin.

In between the performances, the Men in Black provided "Inventions of the '60s" clues which offered an extra fun blast from the past. One such clue was an Easy-Bake Oven, which had a Vegemite sandwich inside. The panel and audience somehow succeeded in bullying host Nick Cannon into trying some of the Australian delicacy, and the look of utter disgust on his face alone made the episode.

Onstage hijinks aside, this being the Group B finale, two people had to go home as the season continues its march to the quarterfinals. First to leave was Bluebell, and all of the panelists used the Vegemite clue to pick an Aussie celebrity. Jenny McCarthy-Wahlberg guessed Naomi Watts, Robin Thicke went with Isla Fisher, Ken Jeong picked Rose Byrne, and Rita Ora chose Kylie Minogue.

In the end, none of them were right. Bluebell was unmasked to reveal '90s icon ("Torn," anyone?!) and three-time Grammy-nominated singer and actress Natalie Imbruglia . The result was particularly ironic considering Imbruglia also competed on The Masked Singer U.K. — and won — while Ora was a panelist on that show, and Ora didn't guess her identity correctly there either.

Bluebell's exit meant Wasp and Goo were sent to the Battle Royale to perform their separate renditions of "I Heard it Through the Grapevine" by Marvin Gaye. In the end, the Wasp won and Goo was sent to be unmasked. But, in the season's biggest twist to date, before he could be unveiled, the panel saved him with the Ding Dong Keep It On bell, sending him to the quarterfinals as well.

This means, so far, Buffalo, Wasp, and Goo will be competing in the quarterfinals, and it also means there will be no more saves this season. Whoever wins Group C will join these masks as the final quarterfinalist for season 12.

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Next up is the introduction of Group C — the final set of five masks for the season — which we will meet in "Who Are You Fest Night" next Wednesday at 8 p.m. ET/PT on Fox.