I quickly strike the match. The flame ignites and a strong smell of sulphur fills my nostrils. But as I’m about to throw it into the strongbox, an icy breath from above blows the match out. I take out another match and light it. The same thing happens.

Shen Da Pai is here. I can feel him. And now I’m trapped like a mouse down a hole.

I step back against the wall, my breath rasping in my throat. I want to cry out but force the sound back down, squeezing it into a hard ball. A wave of nausea makes me groan. I cover my mouth with my hand.

A horrible grating laugh rings out like the point of a knife being dragged across glass. It fills me with terror. Ting Ting has disappeared. My weapons bag is out of reach. And I can’t strike a match to destroy the black talismans in the strongbox. I feel so helpless.

But then I remember something. I still have my ghost song. Nobody can take that away from me.

I take a breath, close my eyes and begin to hum. I imagine walking around the inner garden of Bao Mansion, gathering energy from the rocks, the trees, the plants, the soil and the spring-fed lake. With each breath I feel more and more energised, as if my mind is an open window and fresh air is pouring in.

My ghost song spreads out in front of me and I feel Shen Da Pai moving away, recoiling like a snake that has met a wall of fire.

Now is my chance. I jump onto the boxes and climb out of the hidden room, my ghost song pushing a clear pathway in front of me. I don’t know where Shen Da Pai is. In the dark I grope around for my weapons bag, take out my coin sword and stand up. I turn around on the spot, the sword held in front of me, spreading my ghost song in an ever-widening arc around the room. If only I knew where he was, I could aim the notes in his direction.

I hear Ting Ting cry out in pain in another part of the house. Who is she fighting?

My concentration wavers, and in that split second Shen Da Pai attacks. It’s as if he has his hands around my throat and is crushing my voice box! I try to sing but only a muffled groan comes out of my mouth.

Without eyes to see, and no voice to sing my ghost song, I’m useless to fight Shen Da Pai!

The dark seems to grow deeper, the air in the room even colder than before. Then something brushes my cheek. Long icy fingers run down my face. I feel as if I’m standing on a cliff and Shen Da Pai is an angry sea, battering the cliff with huge crashing waves. Soon I will fall.

If I could see him, I might have a whisker of a chance. I remember Por Por saying that if I want to listen for a ghost, I need to hear the sound behind the sounds around me. So if I want to have ghost eyes, perhaps I need to see behind the darkness, not into it. It’s worth a try.

I relax my eye muscles, not focusing on anything, and try to think of the dark as a curtain that needs opening. I see a chink of light through the folds. It grows bigger and bigger as if it’s rushing towards me, filling the whole room.

Then, amazingly, I see Shen Da Pai standing about a metre away. He’s wearing a long scholar’s gown and holding the black talisman feather I saw in the strongbox. His face is much uglier than I imagined. Deep lines are etched into it. His body is slightly bent as if he’s already lost some of his power. Did Por Por do this to him?

I pretend I can’t see him while I try to figure out what to do next. My coin sword is useless as I’ve hardly practised using it at all. And without my voice – my one true weapon – I have nothing left.

Shen Da Pai circles around me. Every time he waves his talisman feather in the air, a wave of nausea hits me. My whole stomach heaves and I retch again and again as the walls of Bao Mansion shake with his laughter.

I put one hand on my belly to steady it. That’s when I feel the kazoo in my pocket, the musical instrument I bought at the market in Shanghai. I can’t sing … but I can hum!

I turn around so Shen Da Pai can’t see what I’m doing. Then I bring the kazoo to my mouth. I start out really soft and low at first and gradually turn to face him. He shakes his head as if an annoying fly is around him.

My humming grows louder and louder. It is a reedy, buzzing sound.

And it’s working!

Shen Da Pai doubles over as I direct my strange song at his head, then his arms, then his chest and stomach. Lastly, I hit his legs, chopping his knees with short, sharp, buzzing notes. He collapses to the ground.

Quickly I raise my sword over his crumpled body and write invisible talisman symbols in the air. It’s as if Por Por is here, telling me what to do. If he’s not destroyed completely he can come back even stronger than before, she tells me. So I repeat the same symbols over and over again. My arms ache but I don’t stop until he is a wisp of vapour.

Then I take the kazoo out of my mouth and, with one small breath, blow him away.

I hear Ting Ting scream in another part of the house. I run down the corridor and into a small room. I find her hiding underneath an altar table.

‘Where have you been?’ she yells. ‘I’ve been fighting Shen Da Pai for the last half an hour.’

‘What?’ I say, surprised. I squat down beside her. ‘But I was fighting him in the other room. I destroyed him. He’s no more.’

Realisation dawns on Ting Ting’s face. ‘That’s what he must have done. Some ghosts, the really powerful ones, can split in two. But it does weaken them,’ she says. ‘I don’t know where he is now.’

‘He’s over there in the doorway,’ I whisper.

‘You can see in the dark?’ Ting Ting says. ‘But it takes years to master that skill.’

I shrug.

Shen Da Pai limps towards us, his legs weak and wobbly. His face is horribly wrinkled now, as if his flesh might fall off. ‘This time I will get rid of both of you just like I did to your por por,’ he says in a small whispery voice.

With fury I leap out to face him, and Ting Ting follows. She hurls the discus-like weapon through the air, knocking Shen Da Pai off balance. The weapon comes back to her hand like a boomerang. The ghost stumbles and falls. I’m surprised at how calm Ting Ting is, not agitated or emotional like I thought she would be. I strike out with my ghost song now that my voice is free.

Ting Ting glances at me, a small smile of admiration on her lips. Then, raising her knotted rope, she snaps it at Shen Da Pai. It licks the air like a long white tongue, sending the ghost spinning. Shen Da Pai has become a formless grey mass, weakening with every second. He looks for a way to escape. I quickly seal the door, the windows, and all the cracks in the room with my ghost song, weaving a spider-like web over every tiny opening. There is no way out for him now.

And so, with one long, piercing note, I dissolve his spirit forever.