After the Daleks have been driven off the planets in Earth's solar system, Jeff Stone, Mary Stone, and Andy Stone have accompanied the Space Army led by Vel Karneen to the planet Skaro. The Daleks have surrounded their planet with a magnetic field of neutral atoms. All attacks harmlessly bounce off the field. The field has two openings, one over each of Skaro's poles, which the Daleks vigorously defend.
The field does not enclose the entire atmosphere of Skaro, so Jeff Stone realises that the field must have openings to access it. Stone has Karneen direct the Space Army to close off one opening and sends a message to the Daleks threatening to draw off their atmosphere through the other opening. The Daleks surrender and the Space Army prepares to land on Skaro.
- The Stones' spacecraft is named Revenge.
- Break-through! is the only story dating the events in The Dalek Book. It dates the Dalek invasions to 2400, nine years before the "Age of Universal Peace" which began in 2409.
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