Our Scottish intruders pivoted on the spot. ‘Och, and who’d these scunners be then?’ he said to us. ‘Friends of yours?’

I didn’t answer. I was too busy lining up plastic chairs to throw.

‘They’re the Trespassers we were talking about.’ Rani had her sword out and moved until her back was against the wall. ‘It’s probably best if you run.’

‘What?’ The woman looked like we’d asked her to eat a wombat in one bite. ‘Jamie, these eejits want us to run from a fight!’

He drew his sword. ‘Let us take care of this, okay?’ he said to us.

With one hand he reached down and unsnapped his dog’s lead. It had been straining, and once freed, it bolted straight at our cultists.

The two Scots charged after it, galloping at the Ragged Sisters with the sort of war cry that probably froze blood in the Highlands.

Rani hesitated. It was only a second or two, but hesitation in the face of battle was so far from the Rani I’d come to rely on that it probably needed a plaque to mark the occasion.

She bit her lip, glanced at me, then glided after the Scots, reaching them as the first wave of Ragged Sisters hit.

Chaos. Knife-slicing, sword-slashing, Highland-war-crying, cult-howling, dog-barking chaos. Lots of metal clashing on metal, too, and soon grunts and cries of pain. Bodies went sprawling, all robed and masked, as Rani and the two Scots waded into the thick of it. If you’ve ever tried to blend a nice veggie soup but forgotten to put the lid on the blender, then you have some idea of how it went, with Ragged Sisters flying in all directions.

And, no, I’ve never done the lid-off blender thing with veggie soup. It was hummus. Much harder to clean off the ceiling.

Not all the Ragged Sisters were in the fray, though. Four or five of them were keeping their distance. In their hands they had lengths of chain and they were intently watching the progress of the battle.

I didn’t like the look of these guys. Obviously, they were hoping to take prisoners. Rani and I had seen what happens after the Ragged Sisters wrap you up in chains, and it was a situation to be avoided.

Rani and the Scots were too busy to do anything about this chain gang, so it was my big chance to give the Li’l Ace slingshot its first outing.

Like a shadow, I darted from building to building, checking out my route before leaving any cover. By the time I’d reached my target destination, the Photoheliograph House – thanks, handy sign – the fighting had moved away, spilling onto the forecourt of the café, not far from where I’d originally been, but stealthy style is never wasted in a world that doesn’t have enough stealthy style in it.

I peeped around the corner of the PH House, looking for the chain gang and ready to do them some real slingshot-enhanced damage. Trespass in my city, onto my observatory grounds, will you? <Ping!> Would a city that once had the largest steerable telescope in the world put up with people like you? No! <Kapow!> Take that, Ragged Sister! <Zap!> And that! <Wheow!> And there’s one for you to go on with! <Zingo!>

Visualising beforehand is an important part of preparation for physical activity, but I was so busy imagining how I’d pick them off that it took me a while to realise that the Chain Gang wasn’t out on the lawn anymore, and a heavy, very clinky rattle behind me suggested that they’d done some quality sneaking of their own.

Trouble is, even though you know exactly what’s behind you, eventually you have to turn around and look.

Yep, the Chain Gang: five Ragged Sisters with a whole heap of chains and an equal amount of nasty intent. I backed away, fumbling for the ball bearings in the pocket of my jacket, trying to aim while also trying not to shake with fright.

Out of seven attempts, I managed to spang three of them as they ran at me. They dropped, but then the rest were close, then closer, then too close and I was ducking and dodging far too many shiny blades and a length of swinging, heavy chain.

Like surfers, farewells and cute hairstyles, some things come in waves. First it was the arrival of the two Scots. Then it was the appearance of the Ragged Sisters. Right now, it was the sirens and flashing lights of the police as a couple of cop cars screeched up outside the observatory.

The Ragged Sisters backed off, turned, and ran, carrying their chains. After a couple of gigantic, trembling breaths I tried to load up the good ol’ Li’l Ace, but my fingers had some trouble trapping and picking up ball bearings so, instead, I shook a fist. ‘Yeah, and you’d better run, too.’

Felt good.

Rani appeared. ‘We have to go.’

Rani and I ran across the café forecourt and past the grand old red-brick Observatory House. I can go at a fair clip, and Rani is no slouch in anything physical, but I was surprised when the two Scots and their doggo plunged out of the bushes and joined us. ‘What’re you looking at?’ the guy gasped as they pounded alongside us.

‘Wouldn’t you like to know?’ I said. His medicine, I gave him a taste.

Rani directed us off the road that was leading us to the Governor’s Residence, which was probably wise as having a quartet of fugitive ghost hunters drop in on the vice-regal shack in the middle of the night mightn’t exactly be her cup of tea. Or it could be, who knows? She seems like a good sport.

Keeping to the shadowiest of shadows, we wound on past the Ornamental Lake until we got to Alexandra Avenue. Rani was over the fence easily, and I didn’t embarrass myself. The Scots struggled, so we helped them and their dog, which put them in our debt for the rest of their lives to my way of thinking, because my face copped a tongue slobbering. From the dog, and I’m really hoping I didn’t need to tell you that.

The Scots, however, weren’t immediately grateful. They fumed and grumbled, dusting themselves off while Fido sat at their feet with an ‘I have no idea who these guys are’ look on its face.

It was an expressive doggy face. Some sort of canine prodigy, I guess.

The woman leaned over and muttered something in the man’s ear. He shot us a look and muttered back. She punched him on the shoulder hard enough to turn a house brick to powder, and he winced. ‘Aye, aye.’ He took a deep breath and let it out. ‘Kirsten here says we should say thanks for your help, English babe.’

Rani narrowed her eyes. ‘If you want a black eye, keep calling me babe.’

Kirsten hit him on the shoulder again. ‘Excuse my brother. He gets a wee bit too familiar sometimes.’

He grinned. ‘Och, we’re comrades in arms now. Tidy bladework, darlin’.’

Kirsten stamped on his foot. ‘I’m Kirsten McKellar,’ she said, ‘and this is my brother Jamie. We’re from the Loyal Ghost Hunting Order of the Knights Puissant of St Mungo and St Cuthbert.’ She shrugged apologetically. ‘Aye, there are too many “ofs” in there, but that’s the way it is and there’s no changing it.’

‘Anton Marin,’ I introduced myself.

Rani’s wariness didn’t stop her being polite. ‘Rani Cross.’

Jamie scratched his beard, which was full, red and bushy, as if a bunch of rusty steel wool had been stuck to his chin. ‘Marin. So ye’re an actual member of that numpty ghost-hunting family, then, the ones with that bookshop.’

I didn’t ask for an explanation of ‘numpty’. I simply assumed it was a Gaelic word for ‘highly esteemed’ or ‘notoriously brave’.

‘Finding ghosts and then not dispatching them.’ Kirsten shook her head. ‘Incredible.’

‘That’s not how it is,’ I said. ‘We don’t attack ghosts with weapons, slicing them to pieces. We ease their passage more gently.’

They both looked at me the way you’d look at a duck that started solving quadratic equations. ‘You what?’ Jamie actually tugged at his beard in disbelief. ‘Why would you want to be gentle with ghosts?’

‘Maybe it’s because we think there’s not enough gentleness in the world,’ Rani said. ‘And it doesn’t hurt to bring a little bit more.’

That exploded the speech centre of their brains for a while. Broca’s area? Maybe.

‘So what exactly are you doing here?’ I asked. ‘Don’t tell me you’re on a mission.’

Jamie rallied and, after a glance at his sister, said, ‘Told you. We’re on holidays.’

‘A backpacking vacation,’ Kirsten added. ‘We were wandering around your park and Fergus sniffed something interesting.’

They were wandering around parks in middle of the night? I mean, Melbourne has sensational parks, but really?

‘Fergus?’ Rani asked.

Kirsten held up the lead. ‘This is Fergus. He’s our ghost hound.’

They paused expectantly. ‘I can see that we should be very impressed by that,’ I said to them.

‘Of course you should be!’ Kirsten said. ‘Ghost hounds have the ghost sight!’

‘Your dog can see ghosts?’ Rani’s side-eye was majestic, but I could see she really wanted to scrooch his little furry chin.

‘More than that.’ Jamie puffed out his chest. ‘He has a ghost nose. He can sniff out a ghost from miles away.’

‘Get out.’ I stared at the happy hound, who grinned back at us, about half a metre of pink tongue lolling out. ‘This is some sort of leg-pull, right?’

‘He led us to your observatory ghosts,’ Kirsten pointed out.

‘A clever dog.’ Rani gave in and ruffled his ears. ‘Useful in a fight, too.’

‘Careful, I’ll tell Max,’ I muttered to her.

‘Go ahead,’ she muttered back. ‘Max is confident in himself and isn’t the jealous type.’

‘Hold on a second,’ I said to Kirsten. ‘You didn’t bring this dog from Scotland, did you?’

‘’Course we did. We weren’t going to leave him at home. He pines.’

‘We have very strict quarantine regulations in this country, you know.’

‘Och, we know.’ Jamie snorted. ‘Johnny Depp and all that.’

‘We have special arrangements,’ Kirsten said. ‘Expedited isolation periods, expert medicos. It’s all on the up and up.’

I wasn’t totally convinced, but Jamie slapped his dagger. ‘You have any idea exactly who those bampots were, the knifey wallopers?’

‘Have you heard of the Ragged Sisters?’

Kirsten’s face fell. ‘Ragged Sisters? No!’

‘Trespassers of the worst sort,’ Rani confirmed. ‘And it seems as if they’re on the lookout for ghost hunters.’

‘Not for any good purposes, I’ll be guessing,’ Jamie said.

‘Depends on your point of view,’ I said. ‘They’d probably say that sacrificing you to power up their phasmaturgical rituals was a fantastic purpose.’

Their faces fell.

‘You deserve to know,’ Rani said, ‘that at the moment, Melbourne is rather more dangerous than usual. Many, many ghosts are appearing and they seem to be far more aggressive than usual.’

‘Add that to the Ragged Sisters situation and I wouldn’t blame you if you headed out for the Barrier Reef or somewhere,’ I chimed in. ‘Lots to see in Australia.’

‘Aye, good food, too, and tasty coffee,’ Kirsten said smoothly, but then she froze. ‘What’s that noise?’

And isn’t that the sort of thing a ghost hunter just loves to hear after a run-in with a bloodthirsty cult? All I could hear, though, was the sound of traffic over on St Kilda Road. That, and a weird throbbing sound coming from the trees not far away.

Kirsten took a step in the direction of the strange sound, then turned and grinned. ‘That’ll be one of your tawny frogmouths I’ve been on the lookout for!’

‘You’re joking,’ I said and I gave my nerves the ‘Stand down!’ order.

Jamie shook his head, but he was smiling. ‘Kirsten likes birds,’ he explained. ‘She thinks Australia is bird heaven.’

‘Those rainbow parrots,’ Kirsten enthused, ‘the lorikeets, they’re everywhere! So gorgeous!’

Jamie rolled his eyes. ‘I can see us staying here for quite a while.’

‘And keeping an eye out for these Ragged Sisters,’ Kirsten said. ‘Thanks for the warning. Come on, Fergus.’

She flipped the lead, and she took Fergus the ghost hound off in the direction of the tawny frogmouth that was still thrumming away in the shadows. Jamie waved a hand and trudged after his sister.

‘Tawny frogmouth,’ Rani said to me. ‘That’s really a thing?’

‘Yep. Australia, home of weirdness.’

‘So I’m discovering.’

We headed back to the car. ‘I love Melbourne as much as the next guy,’ I said, ‘but this is starting to get a bit bizarre. Are we featuring in some sort of ghost-hunters equivalent of Trip Advisor, attracting visitors from all over?’

‘This city does have its attractions.’

My phone buzzed in my pocket. I fished it out. ‘A ghost hunter’s work is never done.’

‘Pardon?’

‘The Crunchinator has a sighting for us.’