LOONA have dropped a striking teaser video for "#1".

In the teaser, LOONA's Heejin wakes up and finds herself in midair as she climbs up the stairs to an invisible airplane. The audio also suggests fans can expect a more somber tone for "#1", and it's expected to be a track on the girl group's upcoming album.

Watch LOONA's "#1" teaser video above, and listen to their recently released track "365" here if you missed it.