Burnham, Tyler and Saru visit Pahvo to turn its natural transmitter against Klingon cloaking, but the planet's inhabitants have plans of their own.
Klingon cloaked ships are destroying Federation vessels, so Burnham, Tyler and Saru are sent to Pahvo, a planet with a huge natural crystalline transmitter that might be used to detect them. The Pahvans, energy beings devoted to harmony, affect Saru, who for once feels free of fear and turns against his crewmates to keep them there.
On Kol's ship, L'Rell's attempt to help Admiral Cornwell escape fails. Burnham gets the transmitter working, but the Pahvans alter the signal so that it calls the Klingons to the planet as well, believing that bringing the two sides together will produce peace. Kol receives the message and heads for Pahvo. Kirsten Beyer wrote the episode and John S. Scott directed.