1931, Shanghai.
Lu Huaijin is an engineer who has returned to China for three years. He has top-notch skills, but has been suppressed by the monopoly of foreign companies and has nowhere to use them. He is taciturn and his world is filled only with drawings and machines.
Gu Qingwu is the only daughter of a shipping family. She supported the family business at the age of sixteen and fought her way through men's shopping malls. Everyone calls her "Iron Abacus" and no one has seen her fragile look.
During a banquet at a chamber of commerce, she was set up to make things difficult for her: the engine had been tampered with, and if it could not be repaired within thirty days, the family route would not be guaranteed. All foreign companies refused to take over. Lu Huaijin stood up in the corner. The two made a bet - if they repaired the problem, they would build a factory together; if they failed, she would lose everything and he would take nothing.
The engine roared to life on the dock and they became partners.
From the humble maintenance workshop in Wusongkou, to the first diesel engine drawing drawn by the Chinese themselves; from the door-blocking blackmail by the dock gang, to the patent trap carefully laid by foreign companies - they fought side by side in the cracks, and also recognized the same loneliness in each other's souls in getting along day and night.
In his silent company, she learned to shout "help me" for the first time.
With her firm trust, he finally understood that technology was to protect specific people.
In troubled times, everything is drifting. But they became each other's only anchor.
"Leave the drawings to you. Leave the lawsuit to me."
There is no "I love you". But the four words "my partner" carry more weight than anything else.
Intent: In the turbulent waves of the times, two souls who refused to surrender, using each other as anchors, jointly completed a spiritual breakthrough about "guarding".