Mimi walked into the shop at number 12 Celestial Lane, Chinatown. Pillars of gritty books and magazines towered on dusty shelves. One tap would have sent them flying.

‘Yes?’ came a rude voice from behind the counter.

‘I’m looking for Old Ma.’

A red-nailed finger whipped out of the darkness and pointed to the steep wooden stairway at the back.

Mimi made her way cautiously through the passage of books. The stairs reminded her of home. Steep and creaky. At the top was a long hall with doors off to both sides.

She called out timidly, ‘Mr Ma, are you there?’

‘Eh!’ came a raspy voice from the room on the left.

Old Ma sat in a leather armchair, horse hair bursting from its seams. His body was so small and the chair so big and clumsy, in the dim light he looked as though he were perched in the mouth of a giant hippopotamus. At that moment he didn’t look scary at all. Mimi caught a giggle in her throat and covered a smile with her hand.

‘Some cassia tea?’ Old Ma spoke in a voice like rusty old nails. He reached over to the small brass table where an earth-coloured teapot and two teacups as thin as eggshells stood. The sweet scent of the cassia flower filled the musty room as the pale yellow liquid slipped like silken honey into the tiny cups. With a knobbly stiff hand, he nudged one over towards Mimi then looked deep into her eyes.

‘Yesterday, I wake Dragon. He open eye and look at someone in crowd. I very surprise. I turn around, see face of girl. I see Garden of Empress Cassia. Is this true, Mimi? You have seen garden . . .?’

‘Yes it’s true, Mr Ma. The garden is on the footpath near my house. I drew it with the Empress Cassia Pastels.’

Old Ma sank back into his hippopotamus armchair. ‘At last . . .’ he sighed. ‘I wait so long – so many hundred years.’

Mimi was curious to know if it was just Old Ma’s poor English or had he really lived many hundred years?

‘Have you heard story of Empress Cassia?’ he asked before she had time to ask his age.

‘Was she a real empress?’

‘She live long time past in China.’

‘Was she beautiful?’

Old Ma nodded. ‘Most beautiful in land. She have rosebud lips and wide eyes and hair black like night. She live in big palace with much servants and wear yellow gown of Empress. When she eleven year old, her father, big brave Emperor Wu, die in battle against barbarians. Very sad. But Cassia clever girl. She ride horse and shoot arrow straighter than best archer. Swim faster than great sea dragon in Western Cave – and paint like wind dancing on Lake Taihu. She have big heart. Every night, palace gates open wide for great feast. On twelfth birthday people give her present.’

‘What was it?’ Mimi sat on the edge of her chair.

‘Box of beautiful pastels.’

‘The Empress Cassia Pastels. . . of course!’ exclaimed Mimi. ‘Cool. But they couldn’t be the same ones I have.’

‘Only one box in whole of world.’

‘But they . . . they still look like new,’ Mimi said in disbelief.

‘They magic pastels, from ancient world. Empress Cassia draw on throne room wall,’ he continued. ‘She draw plan of beautiful garden. On sixteenth birthday, Garden of Empress Cassia built behind palace. It was garden of perfect balance with long Dragon Wall all around. Every day, Empress Cassia gallop to Pavilion of Mysterious Way. She feed and talk to fish that live in Lake of Secret Dreams.

‘One day, General Hu, head of army, rush into throne room. “Barbarians attack from north. Break through Great Wall!”

‘ “How close?” ask Empress Cassia.

‘ “Two day ride. Our army not strong enough.”

‘Empress Cassia slowly sip cassia tea. She do this to think. “Get all people from city and take to garden. We wait for barbarian there,” she ordered.

‘Two day pass, barbarian arrive at palace wall, smash down gate. But everywhere, empty. Not even crunchy cockroach left crawling on kitchen floor.

‘“Burn to ground!” Big Barbarian Chief cry. They burn down palace.’

‘Then what happened?’ asked Mimi, holding her breath.

‘Barbarian enter garden. Big Barbarian Chief raise sword over Empress Cassia.’

‘No!’ cried Mimi, her hand over her mouth.

‘But wait . . . very strange thing happen. No strength in arm. Sword heavy like five elephants. Big Barbarian Chief get sleepier and sleepier. Whole army fall to ground snoring like bear in winter cave.’

‘Coo-el,’ Mimi laughed. ‘What happened then?’

‘When they wake, they forget where they come from. They think they army for Empress Cassia. Big Barbarian Chief become most loyal general. Peace again all over China. Empress Cassia live very long life. Old as ninety-three. Day she die . . . garden vanish from earth.’

‘Wow. But how could it? Where did it go?’

‘There is space between Heaven and Earth where garden lie like sleeping dragon. Mimi use pastels, garden come back.’

‘But why me, Mr Ma?’

‘Because you have pure heart.’

‘But sometimes I’m really bad. Ask my dad.’

‘You just naughty girl sometime, not listen to Daddy, you not bad. Pastels are like mirror of heart. They not lie. If person is bad, pastels very dangerous so you must always keep them safe and hidden. In every time, pastels wait for just right person to bring Garden of Empress Cassia back. One person like you, Mimi.’

‘Is this true?’

‘Yes, it has been like this for thousand of years.’

‘Mr Ma.’ Mimi stood up, her eyes bright. ‘Come with me, I’ll take you into the garden right now’

‘No, Mimi . . . I cannot,’ Old Ma sighed. ‘Garden of Empress Cassia only for those who hurting inside. It is garden for healing.’

Mimi sat back, disappointed.

‘No matter. In my lifetime I seen many beautiful gardens, Mimi.’ Old Ma raised his cup slowly and took a long noisy sip of cassia tea.

The light suddenly dimmed as the sun sank behind the tall buildings of the city.

‘It’s late. Mum will worry. Thank you, Mr Ma. I’ll come and visit you again.’

‘Goodbye, Mimi. And remember – guard pastels well.’

‘I will. . . oh I almost forgot. I made you a present.’ She handed Old Ma a small scroll.

As Mimi left the shop, a soft drizzle began to fall. Old Ma slipped off the red ribbon and unrolled the painting. Mimi had drawn the Garden of Empress Cassia for him. A miniature version - but with every tiny perfect detail.

The buzz of wings came to Old Ma’s ears. A peacock blue dragonfly dipped its nose into the Lake of Secret Dreams, then flew out of the painting and into the dusty room.

‘Ah . . . Empress Cassia . . .’ he whispered.