Discovery communicates with Species Ten-C through light-based mathematics while Tarka's plan threatens everyone.
Discovery releases a hydrocarbon signal meaning peace near the hyperfield and is pulled inside and enclosed in an orb. 10-C answer with hydrocarbons and light patterns, which the crew decodes as a mathematical bridge language, and they ask why the anomaly was destroyed.
Aboard Book's ship, Reno realizes that Tarka's plan to take the anomaly's power source would destroy the hyperfield and probably Earth and Ni'Var. Book confronts Tarka and is restrained. Ndoye carries out Tarka's plan, Book's ship breaks free, and 10-C stop communicating, though Reno gets a warning to Burnham. Kyle Jarrow wrote the episode and Olatunde Osunsanmi directed.