EXO's Chen continues to get ready for his solo comeback with the 4th mini-album 'DOOR.'

On May 10 at midnight KST, the EXO member released a new concept photo showing a mysterious door. 

Just as announced before, Chen will continue to release more teasers until the album and music video release on May 28, so stay tuned for more teasers and don't miss out on any of them!

SEE ALSO: EXO's Chen begins the countdown to his 4th mini-album 'DOOR' release with teaser scheduler