The entrance to the Shadow Abyss was a stone gate half-buried in earth. A Guild notice reading "Not Recommended for Exploration" was carelessly nailed to the moss-covered door. The four proceeded down the dimly lit passage. Ada raised a hand and stopped. "A trap on the floor... a simple one. I'll disarm it." She crouched confidently and inserted a slender tool. A click sounded. The next moment, the entire floor sank. "Ah." With Ada's short utterance, the stonework collapsed. The four screamed and fell into the deep darkness. "...Is everyone alive?" Iris coughed as she got up. Her armor was unscathed. "It hurts..." Lessa groaned quietly. "I'm fine," Bertoria said, lighting a magical lamp. They were in a vast underground space. The walls were densely carved with unknown characters, and an old stone pedestal sat solemnly in the center. Atop the pedestal, a palm-sized black crystal emitted a quiet glow. Bertoria's eyes lit up instantly. "This is... a summoning stone from the Astral civilization? But they're only supposed to exist in literature...!" "Don't touch it," Ada immediately stopped her. "You're just going to cause trouble again, aren't you?" "I'm just going to examine it. Theoretically, the activation conditions should be quite strict." Bertoria was already approaching the pedestal, cautiously reaching her hand toward the crystal. The moment her fingertip touched it, the stone began to glow intensely from within. Ancient characters floated up one after another, and space distorted. "Wait, is the stone going berserk!?" Iris readied her shield and rushed over. "Bertoria, get away from it!" But it was too late. A blinding light filled the underground space, and a strong gravitational pull drew the four toward the center. Lessa screamed, Ada cursed, and Iris shouted, "This is too much, we're getting out of here!" At the center of the light, something, someone, was being forcibly summoned. —And then, you was there.