2020年2月29日, 是陳家晞廿四歲生日。這天, 有人代表三年前已離世的生父送上生日禮物。而更離奇的是, 這份生日禮物竟是一間偵探社及所在物業單位。家晞打開單位大門, 斜棟青年張諾恆竟然住了進來, 為了不被趕走, 諾恆遊說家晞承繼父業, 改革古老偵探社......
After learning that her dad leaves her a detective agency, Ka Hei goes there for the first time, only to be greeted by a stranger she met on her birthday. While Ka Hei is still feeling lost in life, this very stranger helps to light the path for her. Meanwhile, Lei Zin Kiu has to decide on his next move when his superior deliberately picks on him for reasons unbeknownst to him.
