Watching the map, the duo would see that one lone individual appeared above the holographic room of the Specimen Room, urging the two to go check it out together. Upon arrival, they saw the Specimen Room having been thrashed and in a state of disrepair before the lights were suddenly sabotaged, causing a blackout throughout the planetary base. As Fortegreen and Orange went to fix this problem, Brown and Tan encounters the Shapeshifter, currently masquerading as Fortegreen, wondering around the hallways, turning around to wave at the two. When Tan questioned them about Orange's whereabouts, Brown pushed them back behind them, holding reasonable suspicion.

After the lights were fixed thanks to Fortegreen's engineering profession, the Shapeshifter would finally reveal themselves by striking Brown and restraining Tan against the wall, giving the leader a stab wound on the hand while taunting Tan about their mistake of unknowingly healing the Shapeshifter this whole time.

As the Impostor was ready to pierce their tongue through Brown's head, Lime and Yellow came to the rescue, along with a confused Orange and the real Fortegreen making an eventually appearance afterwards. Realizing they were outnumbered, the Shapeshifter held Tan at gun point and demanded Brown to let them go, which Brown did in hopes of saving the medic's life.

However, Glitchy would suddenly appear out of nowhere and bite down onto the other Impostor's head, forcing them to throw Tan away in response to the pain. The mini Impostor would later let go and reunite with Yellow, eventually mentioning how the Shapeshifter had hurted them.

As the Shapeshifter was distracted by Glitchy's mocking expression, the Polus Crew, Lime, Yellow and Glitchy would engage in a fight with the Impostor, causing an all-out battle to break out.