Peridot makes a disgruntled noise, lashing her tail unhappily. Ignatius's presence is at least some reassurance, though; Peridot doesn't trust Nightshade in the least, but Ignatius has probably worked with the pixie for far longer than any of the rest of the group has even been alive. So, she addresses him specifically.

"Do you believe what she's saying?" the gem asks skeptically. Nightshade has caused a great number of her friends an immense amount of pain, and she really doesn't relish the idea of working with her... But there was a time where she didn't really trust Ignatius either, and she absolutely does now. If he vouches for Nightshade, she'll go along with this.