Tom Horner had the vision to create the greatest show on earth, but was blind to the most precious thing in the world.

One hundred years before silent movies, crowds were already flocking to Leicester Square to see moving pictures.

Ambitious young artist Tom Horner dreams of becoming a celebrated artist like the great panorama painters of the day. But as another smog-filled summer ends, he remains stuck in the ramshackle Bankside studio he shares with his cautious older brother Will Horner. Painting the wives or horses of nobles just about pays their rent, but brings Tom no nearer to realising his dream.

Meanwhile, impresario Robert Barker and his wily business partner John Wyld invest huge sums in an enormous new panorama theatre in the heart of Leicester Square. But their ambitious plans are thrown into disarray when the brilliant, but temperamental, landscape artist, Louis Daguerre quits for another show in Hyde Park. Barker now desperately needs a new artist to create something that will blow the rival show off the map.

Tom finds a way to approach Barker with his idea for a show, but is bluntly rejected. Undeterred, he uses Barker's great vanity as his hook and ingeniously pitches his grand vision of a moving 360-degree panorama of London "as God alone sees it". He signs a weighty agreement with Barker and abruptly abandons his partnership with Will.

With Barker's engineers, Tom constructs an extraordinary studio eyrie, precariously perched high above the Dome and Cross of St Paul's cathedral. Soon overwhelmed by the sheer enormity of the task, Tom has only the doting attention of a young governess, Millie Taylor, to help him realise his vision.

Despite the vicious winter storms and the disruptive machinations of his employer, Tom obsessively labours to complete his masterpiece. He stuns Barker and Wyld, not just by delivering a panorama of London like no other, but by inventing the world's first passenger lift, he creates a whole new way of elevating well-heeled visitors to easily experience the breathtaking view.

From the moment it opens, the Leicester Square show is an unprecedented success and riches seem assured for them all. Staggering in scale, detail and perspective, the finished panorama draws huge crowds and Tom is an overnight sensation.

Amidst the euphoria of his sudden fame and captivated by the allure of Barker's daughter Alicia Barker, Tom heartlessly overlooks Millie, the one true person in his life. The devastating consequences for Tom will reverberate through London's history to the present day.

Leicester Square is the amazing untold story of staggering creative endeavour and the redeeming power of love, set in the beating heart of London.