She leant over him and shook his shoulder. âYou must go now.'
âHuh?' said Callum, blinking. Bo shoved a slice of damper into his hands and put a catskin shawl around his shoulders.
âTravelling gear,' she said in answer to his questioning expression. âYou have to leave.'
Callum sat up and rubbed his face with his hands. âNow?'
As he spoke, another landmine exploded, this time close enough to cause a shower of dirt to fall upon them. Callum shook the dust from his hair and followed Bo to where the Daisy-May stood waiting in the work cave. She could hear the faint whirr of the Wombator, and now, barely audible, the shouts of the approaching Outstationers. The Wombator came trundling back from the lower depths of the caves seeking new instructions.
Bo pointed a remote control at the dusty brown lump of synthetic fur and metal. Its tiny black eyes swivelled as she punched in the new set of directions. The Wombator turned its nose towards a corner of the cave and waddled away again, disappearing into the darkness.
âSince you came, he's been digging,' said Bo. âTo the southeast there are tunnels in an old mine, for many kilometres. He is digging a link. You will not be above ground until you are far, far away, so you will be safe. Safe from their eyes.'
âBut if it's a tunnel underground, how will we know where we're going?'
âThe Daisy-May has many spiffing devices.'
Bo blushed as Callum laughed at her words. âShe has sensors,' Bo continued. âOne works on black body â like infrared â but she also has ultrasound and . . .' She started pushing buttons and the control panel of the motorbike lit up like a Christmas tree. â. . . some sort of radar. Made to pick up something . . . what's that word? Specific. She has a GPS too.'
âA what?'
âA global positioning system.'
âThey don't work any more. Even I know that. The satellites blew when my dads were boys.'
âThis one works on magnetic fields.'
She glanced up at Callum and saw that his expression had changed from amusement to quiet admiration.
âWhere did you learn all this stuff?'
âMy Poppy was an engineer,' said Bo. She shut her eyes, remembering the last time she'd seen him, when he'd turned to face the Outstationers, defending her, as she would defend Callum.
âScuttle,' she said, repeating her grandfather's instructions. âYou must scuttle.'
As the words left her lips, another blast rocked the burrow. âThat was close,' said Callum. âCloser than the last one.'
Bo checked the supplies. She had strapped her homemade panniers to either side of the machine. In one of them sat Mr Pinkwhistle, his shiny snout protruding from beneath the flap.
âWhy bring him?' asked Callum.
âI may die fighting. You take Mr Pinkwhistle with you. He must survive.'
âWhat are you talking about?'
âFirst, I help you to escape. Then I return to defend my home.'
âCome with me, Bo,' said Callum. âYou can't stay here.' He gripped her by both shoulders. She couldn't meet his eye. Beneath her calmness, the breath was being squeezed from her lungs and her heart was pounding. Another blast shook the burrow. Behind them, the living area ceiling collapsed in a crushing roar of fallen rock.
âBo! There is nothing to defend. You have to come with me â all the way.'
Bo looked back at what was left of her kitchen. The oven had imploded, sending a plume of ash and rock into the air. The bookshelves and worn brown sofa were buried beneath a pile of rubble. The Outstationers were pounding against the roof, scrabbling at the rock, trying to force their way through. Her stomach ached and her feet felt as if they were made of lead but she snatched her string bag of hunting tools from a hook on the wall of the work cave and flung them into the panniers.
âQuickly. Help me push the Daisy-May until the Wombator breaks through, or the fumes will poison us.'
Callum took up a position on one side of the motorbike and they began to push the machine along the narrow passageway, into the darkness. Behind them, another explosion destroyed her work cave and they heard the sound of the Outstationers smashing their way through rock. Sweat dripped down Bo's forehead and into her eyes. She glanced across at Callum. He was struggling too, his face tight with strain. She dug her toes deeper into the dirt and tried to take more of the weight of the bike. They heard another muffled thud and the air filled with dust. The caves behind them were collapsing, crushing her hopes.
Suddenly, the air grew clearer and Bo signalled for Callum to stop. She could just make out a flurry of movement ahead â the Wombator.
âHe's broken through.'
She swung one leg over the bike and gestured for Callum to climb on behind her. When his arms were wrapped tightly around her waist, she revved the accelerator. The Daisy-May sprang forward, its lights knifing through the darkness. Dust billowed around them as the bike picked up speed, hugging the tunnel's curves, winding deeper into the earth. Suddenly the tunnel opened out into caves where rusty brown stalactites hung from the ceiling. Bo could feel the shift in their progress. At last they were climbing upwards. She dropped the Daisy-May down a gear and its wheels sent sprays of pelletty rock around their ankles.
They were both blinded by harsh sunlight as the Daisy-May broke the surface. It surged out onto the desert plain like a wild animal released from a trap, fishtailing on the red soil. Bo swallowed the fresh air with relief. The empty wilderness spread out before them.
Bo drove the Daisy-May in and out of the low, scrubby trees scattered across the plain. The air quickly began to heat up as the sun rose higher, and she pushed the release for the shield so they were enclosed by the cool blue cover. She tried to hold onto the sense of elation she'd felt when they broke the surface, but deep inside her, a hollow place was growing with every kilometre that took her further away from Tjukurpa Piti. The desert stretched to a distant horizon, waiting to swallow them both. From far away, they could hear the sound of yet more explosions and Bo knew her home was destroyed. She pictured Tjukurpa Piti, the roboraptors, the Wombator, all her possessions buried under falling rock and plumes of black smoke pouring into the desert sky. A gasping pain rose in her chest, as if she was spiralling away from all that was safe, lost in space.
As if he could read her thoughts, Callum leaned forward and spoke into her ear.
âDon't look back. Don't ever look back.'
Bo set the co-ordinates of the Daisy-May's GPS to the waterhole.
It was the only place outside Tjukurpa Piti that she had ever visited, the only place she knew of where they might be safe. She and Poppy had taken a week to drive there in his solar jeep, but the Daisy-May covered the distance in a matter of hours. The long, rugged mountain range came into view, purple in the distance. Up close, it loomed above them, a towering red. Once they drew near, Bo could read her way by studying every rock and twisted gum tree.
The entrance to the gorge was wide but then the high cliffs narrowed until the two children were enclosed in a red vault with only a strip of blue sky above. In front of them lay the waterhole, its pale green surface dappled with shimmery light. Above, a breeze rippled through the leaves of trees edging the top of the gorge.
âIt's beautiful, isn't it?' she said, turning to Callum.
She balanced Mr Pinkwhistle on the tank of the Daisy-May and jumped down onto the sand. âPoppy brought me here to teach me to swim. We were happy here.'
She stood on the banks of the waterhole and was overcome by a desire to submerge her body in the cool green water, to wash away the dust of Tjukurpa Piti and her grief. In an instant, she had stripped off her clothes.
Callum gasped. âWhat happened to you?'
Bo looked down the length of her body, trying to see herself through his startled eyes. Her limbs were the same honey colour they had always been. She swept her long hair over her shoulder and stared back at him.
âNothing has happened.'
âHave you always been like this?'
âLike what?'
âDid someone cut it off ?'
âCut what off ?' she asked, raising her arms in a gesture of confusion.
âBut you've got . . . ' Callum climbed off the bike and took a step closer, leaning forward to peer at her torso. âIt's sort of like a front-bottom.'
Bo pushed him away. âI do not have a front-bottom!' she shouted. She stormed across the sandy bank and waded into the water until it lapped around her waist.
âThen what happened to you?' persisted Callum, calling to her from the bank.
Bo glanced at her reflection in the rippling water. She folded her arms across her bare chest and spoke over her shoulder. âThat's the way I was born. What's the matter with you? Haven't you ever seen a girl?'
âA girl?'
Bo heard the incredulity in his voice and turned to face him. He was sitting on a rock, shivering.
âCallum?'
But he didn't answer. His eyes were wide and frightened. Bo realised he wasn't teasing.
âWhat is it?' she said, wading out of the water.
âDon't come any closer,' he said, putting one hand out as if to ward her off. âI don't want to catch anything.'
âFrom the water?'
âNo, from you. If you really are a girl, then you might be toxic.'
Bo stood before him, her fists clenched, fighting down her discomfort.
âYou have been with me for days and you are alive and well. Why are you afraid?'
âWhen I was little, I thought maybe my dads made girls up to scare me,' said Callum, averting his gaze as if the sight of Bo's nakedness was too appalling to confront. âI can't believe I've been with you this long and not realised. I knew you were different but . . . '
Slowly, he turned to face her. âNow I understand why you made that joke about “woman's 'twitian”. I laughed. I didn't think anyone had any women's anything. But you weren't joking, were you?'
âWhy would it be a joke?'
âWomen are extinct.'
âExtinct? Like your instinct?'
âNo, that's different. Extinct means everything's gone. Like dinosaurs. There are no more dinosaurs, only fake ones like Mr Pinkwhistle. And there are no more women.'
Bo lapsed into silence and pushed her toe into the sand.
âI feel like I'm dreaming,' said Callum, edging away from her. âI've heard men say they believed that somewhere in the world girls still exist, that someone would discover one some day. My dads said it was crazy, like imagining fossils can come back to life. Dinosaurs, dodos, girls . . . they're meant to be ancient history.'
Bo sat down beside Callum. âI'm flesh and bones. Like you. Not a fossil.' She reached out for one of his hands. He had jammed them both into his armpits and she could feel his resistance but she persisted, tugging one free and then putting her palm against his, forcing him to touch her. âSee, we both have exactly five fingers. Mine are a little longer than yours. Your hands are a little wider. But they're the same. Two hands.'
Then she put her foot beside his. âSame feet too, except yours are like flippers. Bigger than mine!' Lastly, she took his hand and pushed it against her chest. âFeel that? That is my heart beating. Same as yours. I listened to your heart when you were sleeping. You have a strong rhythm. A good heart.'
Callum kept the flat of his palm against her bare chest, his face growing still as he felt her heartbeat. He stared at her, his dark eyes puzzled. âI thought when you read me those stories with girls in them that they were fantasy. But you're like one of those princesses or witches or fairies. Except you must be the last. The last girl alive.'
They stood staring at each other warily. Their silence hung above the swimming hole. Bo flung a pebble into the water and the ripples spread in widening circles. Poppy had told her that her mother and grandmother had died in the plague. He never told her that every girl had perished. She turned Callum's words over and over in her mind. Then she pointed to the end of the swimming hole where the gorge narrowed.
âSometimes animals fall into the gorge. When we came last time, I saw a dead kangaroo floating. It must have washed down into the swimming hole. I thought it was alive, the way it moved in the water, but when I swam out it was only a big, stinky carcass. Things are not always as they seem.'
âSo what are you trying to tell me? Are you saying that you're like a stinking carcass?'
Bo's smile fell away.
She ran into the water and freestyled into the gorge, all the way to where a small cascade of water broke out of the high wall. She dived deep, trying to ignore the fact that Callum was calling her name. She swam until her lungs were bursting and she was finally forced to come up for air.
When she surfaced and looked back, the look of relief on Callum's face made her laugh.
âI thought you'd drowned,' he shouted.
Bo did a leisurely backstroke and pretended to ignore him. He looked hot and miserable, sitting on the edge of the waterhole with his arms wrapped tightly around his knees, watching her as she swam.
âCome into the water,' she called.
âNo.'
âAre you still afraid of me?'
Callum kicked a spray of sand into the water. âYes and no.' âIf no, then come and swim with me.'
âI don't know how to swim.'
Bo waded back onto the shore and reached for his hands.
âI am going to prove to you that girls aren't scary,' she said, pulling him to his feet. She held his face between her hands and stared straight into his eyes. âAnd I will show you that girls have their uses. Take off your clothes. I am going to teach you how to swim.'
Callum let out an exhausted sigh. Slowly, he stripped away his tattered clothes until he was standing naked before her. He didn't look at her body, only her face. Then he held out his hands. Bo smiled and slowly led him into the water, until it was lapping around their waists. âAre you frightened?' she asked.