Shim Cheong struggles with the physical toll of staying on land. She discovers a painful secret from another merman: if a mermaid’s love isn't returned, her heart will eventually harden and stop beating. This revelation adds a ticking clock to her stay in Seoul. Desperate to ensure Joon-jae loves her back, she goes to extreme lengths to understand human emotions, leading to both comedic mishaps and touching moments of vulnerability. Echoes of the Past

The episode culminates in a high-stakes confrontation. As Joon-jae investigates the dark mystery surrounding his family and the villainous Ma Dae-young, he finds himself instinctively jumping in to protect Cheong. In a pivotal scene by the water, the wall between them finally breaks. Joon-jae begins to acknowledge his feelings, not just as a protector, but as someone who is deeply, irrevocably in love.

In the eighth episode of , the tension between the modern-day world and the mythical past reaches a boiling point. The story follows Shim Cheong , a mermaid adapting to life on land, and Heo Joon-jae , a cold-hearted con artist who finds his icy exterior melting. The Heartbeat of the Ocean

The episode ends on a cliffhanger, leaving fans wondering if their love is strong enough to break the "mermaid's curse" or if history is destined to repeat its tragic end.

Meanwhile, Joon-jae’s dreams of his past life as become more vivid and disturbing. He begins to see the tragic parallels between his Joseon-era ancestor and his current life. He realizes that the dangers Dam-ryeong faced—betrayal and the struggle to protect the mermaid—are repeating in the present day. The Turning Point