‘You go too far, Novara. Ptolemy is the father of astronomy, not its wayward son!’ someone called, then others shouted their questions and surprise but all were in vain as none could be heard above the din.

The professor attempted to answer his detractors. ‘I do not suggest this warrants throwing away a whole history of theory.’

Softly at first, Luna once again heard the sound of banging. It came from the group on the opposite side of the room and she saw that the same man was stamping his foot. Slowly the volume in the room dropped until the only sound was the repetitive pounding of one man’s boot. The group parted and gave him space to be seen and heard. He was taller than Luna had first seen, slim and lean like her father, though much younger. His expression was furiously demanding. Luna thought he seemed a bit mad. His intensity was captivating.

‘May I speak?’

The professor nodded and the young man stepped onto a box. Luna realised it was passion in his eyes.

‘I applaud Monte Regio’s contribution to the betterment of the sciences. He has made Ptolemy accessible for the common man.’ There were shouts of agreement, which the man stood silently through until the gathered gentlemen hushed once more. ‘The detail which the learned Professor di Novara brings to our attention, however, leaves me in a most vexatious quandary. If we believe Monte Regio, and I see no reason not to, then it follows that the very father of modern astronomy, as we all rightly name Ptolemy, made mistakes.’

The room erupted yet again with shouting and booing. Men stamped their feet and railed against the speaker.

He raised his voice. ‘If we must accept now that there are errors in his calculations, then I call for a complete reassessment of Ptolemaic theory.’

Luna was drawn to this young man’s fervour. He spoke honestly; there were no dramatics in his delivery. His arms stayed still and he did not cheer to his compatriots like the others who were keen on making noise as much as sense.

Someone in the audience cried out, ‘Still your tongue, fool! Ptolemy’s mathematical treatise is the most important book of our generation. You do well to show more respect.’

‘It may be that I am a fool but I ask you, as indeed I ask myself: what else of this science must we now question? Should we be reconsidering the very basis of our astronomy?’

His words took Luna back to her own musings on paper; she thought he might be the only man in Florence who would not dismiss her as a madwoman. The room erupted in roars of outrage again, men shouting down the speaker, and there was a bustle of activity about him.

Luna turned to her father. ‘What’s happening?’

‘A debate, that’s what’s happening!’ His eyes narrowed. ‘I didn’t expect it to be this contentious.’