Alicia had decided to wear a black cloak to conceal her hair. She didn't want other witches to see the changes in her. That would further complicate matters, as even she did not know what was truly happening, much less explaining to the others in detail. There would definitely be loads of questions coming her way if she were to allow it. Everything was getting confusing and what Zeres told her bugged her to no end. She found it extremely hard to believe. But then, the fact that he was willing to take her with him to see for herself if he's saying the truth made her feel even more confused.
In the end, despite the suspicion and confusion, she could only decide to go along with him in search for that fabled cave that would restore all her lost powers. She had no choice and she had no reason not to go. It was better than confining herself inside the cavern and let her body weaken day after day as more of her powers are drawn out.
