An agent crosses the Thar desert bearing ominous tidings. The spy network is in tatters, he says. Its agents are dead and buried. Kahuta is crawling with ISI. And the nuclear weapons facility has been ring-fenced with Surface to Air Missiles.

But the bad news doesn't end there. London sees a walk-in deliver a mysterious manuscript. Handwritten inside a jail cell in Rawalpindi, it hints at an explosive secret that threatens everything R&AW have worked for. It falls to Sablok to dig deeper and discover its implications.

And just as Mishra and Arora begin to adjust to these developments, one of R&AW's own is betrayed in the worst possible way.