2. Episode 2

A bomb explodes under Jean's car and only Harry's quick-thinking saves their lives. Harry spots a suspicious stranger tailing them who is identified as Randall, a former agent.

3. Episode 3

Harry and Jean arrive in Beirut in hot pursuit of Randall, who is holding Professor Dawson. Meanwhile, Dalby holds a secret rendezvous with Stok, a Russian colonel.

4. Episode 4

Dalby challenges General Cathcart, suspecting American involvement in Dawson's abduction. Harry and Jean head to the Pacific atoll where the neutron bomb is to be tested.

5. Episode 5

Harry is handed over to the Chinese military where he is subjected to a bewildering regime of mental torture. Dalby's love for Dr Lavotchkin takes its toll on his judgement.

6. Episode 6

Harry is tormented by what has been planted in his mind as his mission reaches its bloody climax and the stability of the free world is at stake.