Passion and infidelity are not easily distinguished as right or wrong; just like true love and responsibility, it's hard to draw a clear line. Every summer by the sea, a message in a bottle may drift ashore; just as in everyone's heart, there lies a secret code of love. Let lost and confused feelings rediscover their original sincerity. Every love story is a summer. Unfortunately, Meng Lun is experiencing three summers at once. He juggles three entangled relationships, not only severely hurting two women who deeply love him, but also losing the one true love of his life—Chen Jie. Heartbroken, Chen Jie quietly departs, sealing her feelings in a glass bottle and casting it into the sea, letting love drift with the waves, vanishing without a trace. Meng Lun goes from having it all to losing it all, from the end of fate to its beginning, repeatedly missing chances at true love. Can he rediscover the third summer and hold onto it forever?