Chapter 1.5 was originally gonna be a comic and a single fight, but with the recent readdition of Rosa, she will get her own side story.... well not side story as it's very important but eh..

This takes place not too long after the atrocities that were done by Peisma happened.

At the begining, sans is still recovering from his second encounter and everyone is VERY unnerved by the coming of the 9th human so soon.

Rouxls especially so...

But Undyne sees her worth and spares her, especially after Rouxls said that Rose and Jack knew each other especially well.