6 Kpop Girl Groups (AOA, Mamamoo, Lovelyz, Oh My Girl, (G)I-DLE, plus one secret competitor) compete in a comeback war. In this episode, the groups learn who their competition is for the first time, fight over performance order, and the secret sixth challenger is revealed.

After an inspiring start by Mamamoo and Park Bom last episode, Oh My Girl, (G)I-DLE, Lovelyz and AOA perform their hits. The shocking 66 Drop rule is announced, where a team losing twice in a row is kicked off the show. Oh My Girl gets bad news.

Mamamoo and AOA cover each other. A backup dancer choice raises eyebrows - and rankings, as does a surprise guest.

The lead singer and lead dancer from each group collaborate and compete as units. The singers fight over who gets a duet with Hwasa.

The dance unit leader is chosen, and a legendary choreographer joins the unit. The voice units perform a demo. The groups become closer with each other at a retreat.

The vocal and dance units perform.

The "Fandoras Box" challenge, where each group performs a fan-chosen song.

The winners of the combined Vocal Unit, Performance Unit, and Fandora contests are announced.

All the groups perform their comeback hits. A winner is announced.