The Japanese army strictly controls the enemy-occupied areas, making intelligence transmission extremely difficult. A batch of life-saving military medicines sustains the safety of tens of thousands of soldiers and officers on the front lines. The Suzhou Grand Canal becomes the only vital route for material transit, and the mission is fraught with extreme danger. Team members must not only finalize the transportation timing and plan secret routes, but also design difficult-to-decrypt contact codes. Operating entirely under the strict surveillance of enemy troops, they fall into perilous situations several times and cleverly escape relying on courage and strategy. Everyone faces difficulties head-on, strives to conquer one obstacle after another, and vows to complete this near-impossible top-secret transportation mission.