Iris remembered Abby's reaction when she asked about Rei the first time, she looked terrified, as if there was a big, dangerous secret there, but what she told them just now it felt so shallow. Yes, that was also a big secret to know about the dark magic within the Holy Kingdom, but then it was not something crucial.
If that was the only secret, then Abby's reaction at that time didn't make any sense. She looked horrified and didn't want to talk about it at all. It was not just a secret.
"You are trying to hide something. That's not the secret." Iris stared at Abby closely. "You always give us a piece of information and then another piece when you are being cornered and then another piece. We don't want your crumbs of information. You are here to ask for our help, but if you don't even trust us, you better leave." Iris reminded her about her intention to come here in the first place and why they were having this conversation.