Erika's face lit up a bit for a moment, but returned to her normal self. An idea came up to her. "Actually...there is one way. Yes...this should be more than enough..." Erika said with a low voice, her eyes fixed on Greap. She took out that letter with the riddle. "Let's see...'On the first twilight, the one with the key shall offer up six as a sacrifice...' That shall do, in fact, I might know where this would happen. So, I will be the one to agree to the deal," she read the part of the riddle, thinking it would work out, holding out her finger to prickly.