The team are devastated by the loss of Ralf and are unsure whether they want to continue with project Stormshield. However, hurricane season is now under way and a much larger hurricane is threatening Miami. Despite their emotions, the team are keen to see how far they can take their experiments. If successful, they will surely save hundred of lives. The manipulative Katzenberg urges them to try out other ideas.

Distant perturbation is Dan’s baby – this involves laying trails of carbon black in the skies over the West Coast; the carbon absorbs sunlight and will trigger the formation of a weak weather system that would move across the country, growing more powerful as it does. By the time it reaches the East Coast, it should possess enough energy to push the hurricane out to sea.

As Dan and Munish run the calculations, Katzenberg secures permission from the Floridian Senator to allow the experiment to take place. It will mean large parts of the Southern States are flooded by the experiment, but do they need to know why?

Permission is granted but, before the B52’s take-off, Lance warns that another weather system has developed which will throw out their calculations. He urges Katzenberg to halt the experiment, but he refuses. Outraged by Katzenberg’s irresponsibility, Dan pulls the plug, shutting down their computer system and resigning from the project. The rest of Stormshield follow.

However, when a suspicious weather system develops, the team realise that someone has gone ahead with the experiment, leading to devastating consequences. The hurricane will be deflected, but it will interact with another weather system that will nudge it up the coast. It’s getting bigger, more powerful, more destructive and it’s heading for New York City.

Sunday 22 April
9.00-10.00pm BBC ONE