On April 5, Dreamcatcher released their second single album Fall Asleep in the Mirror, and its title track "Good Night". Dreamcatcher on August 22, 2017 From left to right: Dami, Handong, Gahyeon, Yoohyeon, SuA, Siyeon, JiU Dreamcatcher released their first EP under their new name titled Prequel on July 27. The album contained six tracks, including the lead single "Fly High". The album debuted at No. 5 on the Billboard World Albums Chart and peaked at No. 1 on the US iTunes K-Pop Top 100 Chart. On August 1, Happyface Entertainment announced that Dreamcatcher would hold their first world tour after wrapping up their promotions for 'Prequel'. On January 4, 2018, Happyface Entertainment revealed that Dreamcatcher would release a new digital single dedicated to fans in celebration of their first anniversary on January 12 composed by Ollounder (오종훈) and Leez (이수민), who also composed Dreamcatcher's previous title tracks "Chase Me" and "Good Night". On January 12, Dreamcatcher released their first anniversary digital single "Full Moon", alongside a promotional video. The single immediately charted highly on the iTunes Top 100 K-Pop charts in many countries worldwide and ranked No. 16 on the Billboard World Digital Song Sales chart. In March 2018, the group announced their official fandom name to be "InSomnia".On May 10, Dreamcatcher released their second EP Escape the Era. Their second EP has six tunes, including the lead single "You and I" and its instrumental counterpart. On February 13, Dreamcatcher released their fourth EP, The End of Nightmare. The album culminated in their new single - 'PIRI', a song showcasing Dreamcatcher's signature rock acoustics and incorporation of music from its namesake musical instrument. In early September, Dreamcatcher released a series of pictures teasing a new release. Following that, a comeback scheduler was unveiled - confirming the release of a new special EP, Raid of Dream. On September 11, the group released their first Japanese full album titled The Beginning of The End, which includes Japanese versions of most of their title songs and 2 new Japanese singles. The music video for the track 'Breaking Out' was released 2 days prior to the album release, and Dreamcatcher held a showcase to promote and perform the new Japanese songs broadcast on LINE Live. Together with the release of Dreamcatcher's Korean comeback album Raid of Dream, the music video of their new Korean song 'Deja Vu' was unveiled on September 18. A Japanese version of the song was also uploaded simultaneously. This song is a formal collaboration with the mobile game 'King's Raid'. On February 3, Dreamcatcher revealed their teaser schedule for their first Korean studio album. This first studio album—Dystopia: The Tree of Language—was released on February 18, together with the music video for "Scream", an uptempo EDM-rock song. The album featured eight new original songs, packaged with Dreamcatcher's previous two fan songs "Full Moon" and "Over The Sky", as well as Siyeon's solo debut song "Paradise". it was marked their first part of the "Dystopia" series and first album of the group since 2017, Dreamcatcher's third Japanese single, titled 'Endless Night', was released on March 11, after its official music video was released a week earlier via ponycanyon's YouTube channel. On March 12, Dreamcatcher announced support for Handong's participation in the Chinese Idol-producing show 'Youth With You'. From March 20, Dreamcatcher did a 2-week-long follow-up promotion on "Black or White", a song from their first studio album, days after promotions for 'Red Sun' and "Scream" ended on the second week of March. On July 30, the second installment of the "Dystopia" series, The group revealed their teaser schedule for their fifth EP. The fifth EP, Dystopia: Lose Myself was released on August 17 and became their best-selling album to date. The music video for the track 'BOCA' from their fifth EP Dystopia: Lose Myself was released on August 18. On October 16, Handong officially made her return to the group. Handong also released her solo debut song, First Light of Dawn, on October 19. With the third installment, the group announced their new comeback with their sixth EP, Dystopia: Road to Utopia, and its lead single "Odd Eye", which was released on January 26, 2021. On July 30 2021, Dreamcatcher made their comeback with the song "BEcause" and the special EP Summer Holiday.