At a multinational military meeting, General Chang explains that humanity’s immediate war is against the human members of the ETO, not yet the distant Trisolaran fleet. The key objective is to seize the Trisolaran messages stored on the ship Judgment Day without giving the crew time to destroy the data. Officers consider spies, ball lightning, neutron bombs, nerve gas, concussion weapons, and infrasonic attacks, but each plan fails because it is too slow, too destructive, or too uncertain.

Shi Qiang, dismissed by some of the foreign officers as merely a policeman, argues that the problem requires criminal-style ingenuity rather than conventional military thinking. Using the Panama Canal as the setting, Shi Qiang proposes stretching multiple nanofilaments made from Wang Miao’s "Flying Blade" material across a narrow channel so that Judgment Day will slice itself apart as it passes. After the room grasps the idea, Wang confirms that he has enough nanomaterial, and the group refines the plan by choosing the Gaillard Cut as the ambush site and accepting that some unavoidable casualties, including innocents, may result.

Four days later in Panama, Wang waits with Colonel Stanton above the canal while disguised crews prepare the "zither," the code-named array of fifty nanofilaments. Stanton tries to distract Wang by talking about Panama and about how the knowledge of the Trisolaran invasion has made past human wars seem trivial. Wang remains focused on the approaching ship, dreading the consequences of his own invention and briefly hating Shi Qiang for conceiving such a brutal use for it.

When Judgment Day passes through the invisible nanofilament plane, the damage is not immediately obvious. Then small signs appear: an antenna breaks, a crewman is cleanly cut in half, and the engines begin to tear themselves apart. The ship loses control, crashes into the shore, and separates into more than forty half-meter slices that collapse over one another. Soldiers and helicopters move in at once, suppress fires, and begin searching the wreckage. Looking through binoculars, Wang sees the cut surfaces of the wreckage shining like mirrors in the red evening light.

Three days later, the narrative shifts back to Ye Wenjie’s interrogation. Ye admits that she never truly understood Trisolaran civilization and had projected moral superiority onto it because of its scientific advancement. The interrogator tells Ye that the operation killed Mike Evans but succeeded in recovering about twenty-eight gigabytes of intercepted Trisolaran data, encoded in a format readable through Red Coast’s system. Ye is stunned by the volume of information, and the interrogator prepares to show Ye evidence that the reality of Trisolaran civilization differs sharply from her idealized hopes.