He has one option and one option only - stop the threat, or everyone will die. Avner Ehrlich, the Mossad's "operator," is inserted into Tehran, on a mission to eliminate Professor Hamdani, a senior Iranian nuclear scientist. His task becomes increasingly complicated, and Avner is called to abandon his mission and return to Tel Aviv. But, being Avner Ehrlich, he decides to ignore the command and stay on course. A violent battle develops in Hamdani's home, in the center of Tehran. With Ehrlich's gun pressed to his head, Hamdani's son comes running in and hangs desperately onto his father. Ehrlich lowers his weapon and retreats into the darkness. In the debriefing at Mossad headquarters, Ehrlich takes responsibility for the failed mission and is suspended from his position. However, it isn't long before he is summoned urgently back into action when it turns out that Hamdani is in Moscow with Colonel Rasputin, and together they have armed a stealth submarine with the "Czar's Bomb" - the biggest nitrogen bomb in the world. The submarine is making its way to join the Russian military fleet in Syria, but its true assignment is to bring destruction to Tel Aviv. For Ehrlich, one option remains - stop the bomb, or everyone will go to hell.