Two years after their debut singles, NCT U returned on Sunday (Feb. 18) with some lineup changes and the dramatic leadership anthem "Boss.”

“Boss” is the first of six songs planned to come out of the larger NCT 2018 group, a revised platform through which NCT’s subgroups will release music this year; an album is expected to be released in March. It is a dynamic, electro-hip-hop track about being leaders and features lyrics written by members Mark and Taeyong.

The paunchy, chanting chorus of the bass-heavy dance single is offset by dulcet vocals and charismatic raps, offering up the latest “SMP,” or SM Performance, single from an SM Entertainment act. It ends with a heavy synth conclusion almost entirely void of vocals that serves as a venue for the aggressive choreography featured in the music video.

With an overall focus on the group’s rappers and the seven members' stomping, in-your-face dance moves, the hostile song culminates in a fight between the younger members (Jungwoo, Mark, and Lucas) and the older ones (Taeyong, Jaehyun, Doyoung, and Winwin), and shows Mark and Taeyong actively fighting one another atop of a table. Throughout the video, the members alternate between stylishly preppy, logo-bearing athleisure outfits and black uniforms, a nod to the figurative battle they are fighting.

Upon its release, “Boss” trended worldwide on Twitter with a variety of hashtags as fans heralded NCT U’s return as a group and the formal start of NCT 2018.

Currently, there are three NCT groups: U, 127 and Dream. Since its first pair of singles in 2016, several NCT members have released songs under the NCT U title, but this is the first time since their debut that NCT U has returned as a group since the release of the standouts “The 7th Sense” and “Without U.” “Boss” is the first song released by NCT 2018 and features the second NCT U lineup. The first iteration, which dropped the first-ever NCT singles back in 2016, featured six members, including Taeyong, Mark, Jaehyun and Doyoung. Lucas and Jungwoo are two of the three new NCT members for 2018, along with a new Chinese member, Kun.

Watch the music video for “Boss” below.