On this night, Millie had followed Seri making sure to stay hidden in the shadows. She overheard the conversation Seri had with Gilyn and quickly understood the situation. She had been prepared to strike at Gilyn if he intended to actually kill Seri.
However, he let Seri go and even heard her out before leaving.
What happened next had Millie completely at a loss for words. Even if her own mental stability was questionable, she was stunned to see Seri conversing with thin air. Was she so drunk that she imagined someone else there?
Curious, Millie continued to follow Seri.
However, after the explosion not only did she lose sight of Seri, but she was also being chased down by the men fleeing the burning building who assumed it was her who set it on fire. Once she lost the men following her, she realized she had lost Seri's location.