LI SHI-CHUN (Frankie Lam), who has studied herbs since he was a little boy, loves a girl TUNG CHING (Michelle Ye). However, he is already engaged to NG MO YUNG (Selena Lee). He plans to break off the engagement and reveal his feelings to Ching after taking the imperial civil examination. Unfortunately, when he returns home after the examination, Ching has already agreed to marry his brother LI GWOH-CHUN (Ai Wai). Chun has no choice but to marry Yung. He becomes the student of a renowned doctor Little Buddha, who turns out to be Ching’s adopted father. Chun finds out that the old medical books are full of mistakes. There are also all kinds of fake herbs in the market. Therefore he decided to write a book called the Compendium of Materia Medica. He is appointed as an imperial doctor in the palace by the Duke of Chor. However his ambition of writing the Compendium of Materia Medica is interrupted after he has offended influential official Yim Sung. He even has to run for his life. An outstanding student PONG HIN (Kenneth Ma) from the imperial medical school accompanies him as a follower. Chun lives in seclusion to practise medicine and study herbs. He is determined to finish the Compendium of Materia Medica even though it might take him his whole life.