ATEEZ released a 30-second video titled "ATEEZ 'Zero: Fever Part 1' Diary Film Teaser" on its official SNS channel yesterday afternoon.

The video showed Hong Joong sitting alone on a sofa at an abandoned factory. Surprised to see something, he faced a silhouette of a man walking toward him, with his two feet up on the sofa and close to his back.

A man wearing a mask and a black fedora that came up to Hong Joong with his back against the light. The moment his shadow came close enough to cover the Hong Joong behind him, an hourglass suddenly stuck out. Hong Joong looked up at the man with doubts and surprisingly saw the face in the mask that looked just like him.

And on the screen that was briefly blacked out, a fast-flowing, shining sand clock appeared, raising expectations for the main film of the "Diary Film."