Mat Lawrence and Mac McNally are the best of friends - except on this one night at Stanford Hall in Leicestershire when their respective firework installations send thousands of pounds up in smoke in their 15-minute displays to music.
They are competing in the annual Pyromusical Firework Championships.
The public watches and votes via mobile phones for this year's champion.
Rob Brydon tells their story - from the visit to China to pick the latest inventions, to six months later, when, in pouring rain, wires are laid and fuses primed.
Who will win? Will the fireworks even go off?