A group of British scientists work to develop a radar system. School for Secrets tells the story of the 'Boffins' - research scientists - who discovered and developed radar and helped avoid the German invasion of Britain in 1940. Five different scientists, led by Professor Heatherville (Ralph Richardson), are brought together to work in secrecy and under pressure to develop the weapon. Their dedication disrupts their family lives as they are forced to sacrifice everything to make a breakthrough. Their success is illustrated by the effect radar has on the fighting abilities of the RAF over the skies of Britain in the summer and autumn months of 1940. However, Germany is also planning its own radar capability and British commandos are dispatched to strike at a Nazi installation. The scientists then complete their work just in time for the Battle of Britain.