Gan Er goes out and learns the craft of growing citrus, returning to the barren Citrus Village. The southern slope behind the village has been abandoned for years, with villagers only growing coarse grains and relying on the weather to eat. Gan Er proposes planting citrus, which is opposed by Gan Bo, who believes there is no road to sell them. Gan Er insists on trial planting, clearing and reclaiming the slope, grafting and raising seedlings, pruning branches and thinning fruit with A Shi and Da Niu. After enduring pests and rainy weather, they finally harvest citrus, juice it, make jam, preserves, pastries, brew wine and boil paste, opening up sales channels and leading the whole village to turn the barren slope into a citrus orchard, letting the fragrance of citrus float all over the mountain village.