On November 28, 2023, JYP Entertainment announced Nmixx would be releasing their second EP titled A Fe3O4: Break and its pre-release track "Soñar (Breaker)" on January 15, 2024, and December 4, 2023, respectively.[2][3] On January 2, 2024, a short animated film titled Fe3O4: Declaration teasing the release of the EP was released,[4] which is followed by a trailer film titled Sense Break Aware and its accompanying promotional pictures two days later.[5] The track listing was released on January 6, with "Dash" announced as the lead track.[6] On January 9, a performance video for the track "Run for Roses" was released.[7] Two highlight medley videos, an acapella version and a normal version, were released on January 11 and 12 respectively.[8][9]
^Seon, Mi-kyung (November 28, 2023). "엔믹스, 내년 1월 15일 컴백 확정..12월 4일 디지털 싱글 선공개" [Nmixx confirms comeback on January 15th next year...digital single pre-release on December 4th] (in Korean). Osen. Archived from the original on November 28, 2023. Retrieved November 28, 2023 – via Naver.
^Seon, Mi-kyung (January 2, 2024). "'컴백' 엔믹스, 세계관 세 번째 시리즈 'Fe3O4' 서막..서사 확장한다" ['Comeback' Nmixx, worldview's third series 'Fe3O4' begins...expands narrative] (in Korean). Osen. Archived from the original on January 2, 2024. Retrieved January 2, 2024 – via Naver.
^Hyun, Jeong-min (January 4, 2024). "엔믹스, 미니 2집 'Fe3O4: BREAK'로 새 모험 알린다" [Nmixx announces new adventure with 2nd mini album 'Fe3O4: BREAK'] (in Korean). Sports World. Archived from the original on January 5, 2024. Retrieved January 5, 2024 – via Naver.
^Kang, Seo-jeong (January 6, 2024). "엔믹스, 컴백 타이틀곡='DASH'..DAY6 Young K 참여 2번째 미니앨범" [Nmixx, comeback title song='DASH'..DAY6 2nd mini album featuring Young K] (in Korean). Osen. Archived from the original on January 6, 2024. Retrieved January 6, 2024 – via Naver.
^Choi, Ji-ye (January 9, 2024). "전원 에이스 그룹이라던데...엔믹스, 퍼포먼스 어떤가 봤더니" [I heard they are all ace group... Nmixx, I looked at the performance.] (in Korean). Ten Asia. Archived from the original on January 9, 2024. Retrieved January 9, 2024 – via Naver.
^Yoon, Jun-ho (January 11, 2024). "엔믹스, 미니 2집 하이라이트 메들리 아카펠라 버전 공개" [Nmixx releases 2nd mini album highlight medley a cappella version] (in Korean). Ten Asia. Archived from the original on January 11, 2024. Retrieved January 11, 2024 – via Naver.
^Seon, Mi-kyung (January 12, 2024). "'컴백' 엔믹스, 6인 6색 환상적인 음악 보석함 열린다" ['Comeback' Nmixx, 6 people and 6 colors fantastic music treasure chest opens] (in Korean). Osen. Archived from the original on January 12, 2024. Retrieved January 12, 2024 – via Naver.