MONSTA X is continuing to release teasers for their impending comeback!

On April 19 KST, the group's agency Starship Entertainment unveiled the 'Chapter 1' trailer for their upcoming album 'Fantasia X.' In the clip, member Hyungwon is seen in a dark alley after receiving a pair of keys inside a mysterious envelope. He hears a telephone ringing in a nearby booth and soon realizes that the keys are meant for him to go inside it. However, once he answers the phone, he suddenly vanishes.

Meanwhile, 'Fantasia X' is set for release on May 11.

Check out the teaser video above!