Luna dug her chin into the sweet warmth of the cloak, realising that it was him she could smell in its muskiness. They sat in silence, listening to the sounds of small animals scurrying from nocturnal hunters and the tick of insects in the grass. The ground was cold and Luna’s boots were already damp.

She wondered how long they’d sat there when an owl hooted. Nicolaus stood then and craned his neck. He turned and helped her up.

‘There, it is begun.’

Luna stood beside him. She couldn’t see the professor at all. As the minutes passed, the fullness of the Moon ebbed. Luna’s scalp prickled at the shifting hues. She took her eyes from the sight for only a moment. Nicolaus was looking at her.

‘Watch now,’ he whispered and she turned back to the view before them. Slowly, steadily, the Moon crossed into the Earth’s shadow. That was the science of it, but there was so much more to be felt in the living of this moment. The Moon dimmed and its fullness ebbed with steady progress. Even the animals had quieted. There was only the Moon and her body anchored to this hill, whilst so far above, deep into the fifth essence that was the Lord’s house, the Moon shifted farther into shadow. Luna swayed, mesmerised, and reached out a hand, which Nicolaus took. They watched for the moment when the Moon would disappear into darkness. But something else happened that left Luna gasping.

‘It is as if it’s sprinkled with a bonfire’s burning embers.’ Her voice was hushed. Nicolaus squeezed her hand.

‘A Moon of blood red,’ the professor intoned, as he came closer in the dark. ‘A full lunar eclipse. Rare indeed.’

Nicolaus dropped her hand at the sound of the professor’s voice and went to stand with him. Luna couldn’t feel her feet, so cold was she, and her cheeks stung, but she didn’t want to move. Even breathing seemed an intrusion on nature at that moment. She stayed where she was, staring up in wonder at the Moon, no longer pale but daubed with a rosy hue she’d not thought possible.

Nearby the men were writing down measurements. Ptolemy had tracked the Moon through three eclipses. It was written in the Almagest. That’s how he’d determined its motion and size; the Moon appeared larger when it was closest to Earth and smaller at its most distant point. She thought this would be a good exercise for Nicolaus to replicate, to test his suspicions of error, if he could be assured of another two eclipses of similar duration and geometry.