【Limited sale until December 16th!】 ※ Items on sale can be purchased immediately without comments! ※ Please note that items may be deleted without notice due to inventory management. If you wish to purchase, please proceed with the purchase process! ※ We are sorry, but price reductions are not possible + first come, first served. Readers who enjoyed solving the mysteries in extreme situations are struck by a shocking "truth." Hajime, who visited an underground structure in the mountains with a friend and a cousin, spent the night in the underground structure "Ark" with a family he met by chance. The next morning, an earthquake occurred, the doors were blocked by rocks, and water began to flow in. The "Ark" will eventually be submerged. Just then, a murder occurred. They can escape if they sacrifice someone. The time limit is about a week. The sacrifice should be the culprit. -- Everyone except the culprit thought so.