Nine years ago, the war between the Kingdom of Night and the Kingdom of Rivers tore Àn'yīng's family apart, leaving her mother barely alive and a baby sister to fend for. Now the mortal realm is falling into eternal night, and mó--beautiful, ravenous demons--roam the land, feasting on the flesh of humans and drinking their souls. Àn'yīng is no longer a helpless child, though. Armed with her crescent blades and trained in the ancient art of practitioning, she has decided to enter the Immortality Trials, which are open to any mortal who can survive the journey to the immortal realm. Those who complete the Trials are granted a pill of eternal life--the one thing Àn'yīng knows can heal her dying mother. But to attain the prize, she must survive the competition. Death is common in the Trials. Yet oddly, Àn'yīng finds that someone is helping her stay alive. A rival contestant. Powerful and handsome, Yù'chén is as secretive about his past as he is about his motives for protecting Àn'yīng. The longer she survives the Trials, the clearer it becomes that all is not right in the immortal realm. To save her mother and herself, Àn'yīng will need to figure out whether she can truly trust the stranger she's falling for or if he's the most dangerous player of all ... for herself and for all the realms.