<□>□□st as Li Lei and □□n Meimei t□ought they had s□en everything□the □□□si□n had□□o □□fer,□they stumb□□d □pon a hidden □rap□oor in□□he fl□or. With h□a□ts p□un□ing, they open□d the trapdoor □nd □escen□ed in□o a dar□, mus□□□tu□nel below. As □hey □avi□□ted through the□w□nd□n□ □ass□ges, t□e dim light of their fla□hlig□t reve□led ancient art□facts a□d cr□ptic□symbols on the wa□ls. The f□rth□r they ventured, the mor□ the□ re□li□ed they □e□□□□ot□□lon□ i□□the □unn□l.