The sun has finally set for Sleeper Agent. After five years together, the alternative rock band has called it quits as its lead singer Alex Kandel tries to make it as a solo artist on NBC's The Voice.

On Tuesday night's episode (Sept. 29) of the popular reality competition, Kandel, a familiar face to indie rock fans, appeared on The Voice as a contestant.

Her appearance on the show seemed to imply that Sleeper Agent was done, surprising fans. Noting that she joined the group when she was just 16 years old, Kandel said that despite playing Coachella and The Late Show with David Letterman, the band "hit this plateau and we decided to part ways and try other things." She talked about the band in the past tense and said her time in Sleeper Agent is over.

The band later confirmed that news on its Facebook page, noting that it was "the best five years."

"The 5 best years of my life... so far." Lurve, Tony

Posted by SLEEPER/AGENT on Tuesday, September 29, 2015

Though Sleeper Agent had critical acclaim with the release of its debut album Celebrasion, the band's sophomore effort About Last Night failed to pick up steam.

Kandel's debut on The Voice came with a performance of the Echosmith song "Bright," and though she was notably nervous without her bandmates, she managed to get chair turns from Gwen Stefani and Adam Levine. She eventually joined Team Gwen.

Kandel will continue to compete on The Voice as a member Stefani's team. The battle rounds of the show, the next time Kandel will appear, will kick off on Monday, Oct. 12.

Join the Discussion