It's not my golem, Sunday thought sourly. *Is that going to be a problem for him . . . I mean, it?'

Dorcas nodded sagely. *He won't automatically be ambushed, not in daylight. But then again one or both of the hammerheads may decide to have a go at him, if it thinks the likelihood of reprisal is small. Which it would be a the golem's not even a warmblood a but the hammerheads probably don't know that.'

*Probably?'

*Don't put anything past these things. Sniffing comms traffic, distinguishing between a human pilot and a chinged proxy a that's within their cognitive bound, just as it's within ours.'

Sunday brushed a gauntleted finger against the largest icon on the map. *The Aggregate?'

*Yes,' Dorcas said.

*Maybe it's me, but it looks closer than it did yesterday.'

*It's covered some ground overnight. It probably doesn't mean anything.'

*Probably,' Sunday echoed once more.

*It can't know what we're doing here,' Dorcas said. *It can't know, and even if it did, it wouldn't be interested. I told you, it's like a city-state. We're nothing to it.'

Sunday watched the drill bite deeper, its progress plain to the naked eye a it had reached at least a metre into the ground, perhaps more. That there was something down there was now beyond doubt. The radar and seismic profiles had improved since Dorcas's first detection, and now revealed what appeared to be a purposefully buried box, not so very different in size and proportions from the container Chama had uncovered on the Moon. A rectangular shaft must have been excavated, the box lowered into it lengthwise and the waste material dropped back over it, before being tamped down. With better equipment, they might even have been able to peer inside the box without bringing it to the surface. Not that it mattered: they'd have the thing in their hands before very long. Gribelin was digging a circular shaft slightly wider than the original bore, and he would stop short of the item itself, for fear of damaging it or triggering some destruct mechanism or booby trap. To be sure, they would send in the proxy Gribelin carried attached to the front of his vehicle.

*When do we hit it?' she asked.

Gribelin stared at the drill for a long while before answering. *Sixty, seventy minutes.'

*When I asked you before, you said it wouldn't take more than an hour.'

*I said it wouldn't take much more,' he snapped back at her.

*Golem's fifty kays out,' Dorcas said levelly. *If the hammerheads are going to do anything, we'll know about it soon enough. Maybe luck's on your golem's side.'

*If we didn't have to drill here, maybe we could drive out and meet the golem halfway,' Jitendra said, stamping his feet nervously, as if the cold was starting to reach him through the insulation of his suit.

*And then what?' Dorcas asked. *Use reasoned persuasion?'

*I was thinking more along the lines of a reasoned kick in the teeth.'

*There's no Mech to stop you, but you'd still be in a world of trouble once news got back to the Surveilled World. And we don't know that the golem doesn't have a human or warmblood guide with it.' Dorcas nodded at the whirring drill. *We'll see this through to the bitter end. It's not as if it's likely to be anything worth fighting over.'

*You still don't believe we'll find anything,' Sunday said.

*If that box has been down there for a hundred years,' Dorcas said, *then everything I know about the Evolvarium is wrong. And I'm afraid that's just not the way my world works.'

*Much as it pains me to agree with the good captain,' Gribelin said, *she does have a point.'

There had been days that seemed to pass more rapidly than that hour. Watching the drill was like watching a kettle. Eventually Sunday gave up and walked away from the site, as far as she dared. Even when she was two hundred metres from the truck, she could still feel the vibrations from Gribelin's equipment. Other than the rock plume, the sky was clear and cloudless, darkening almost to a subtle purple-black at the zenith. Pavonis Mons was a gentle bulge on the horizon a underwhelming, or would have been were she naive enough to have expected anything more spectacular. She was already on its footslopes. The mountains of Mars were simply too big to see in one go, unless one was in space.

Give her Kilimanjaro any day. At least that was a mountain you could point to.

The vibration stopped. She looked back just in time to see the plume attenuate, the last part of it bannering through the sky like a kite's tail. She watched Gribelin push the drill back out of the way, nothing in his unhurried movements suggesting that there'd been a fault with the machinery.

She walked back to the drill site. By the time she got there, Jitendra and Dorcas were leaning at the edge of the fresh hole, hands on knees as they peered into its depths.

*The good news,' Dorcas said, *is that one of the hammerheads took the bait.'

*And?'

*It wasn't a clean kill. The vehicle is still approaching, although not as quickly as before. But it's damaged, and the other hammerhead may be taking an interest.'

*Will there be repercussions?'

*Reprisals? Probably not. Your golem resumed movement before sun-up, which is asking for trouble in anyone's book.'

*I hope no one else was hurt.'

*Their fault if they were,' Dorcas said.

Sunday took care as she neared the freshly dug hole. It was only about sixty centimetres across, but easily wide enough to become wedged in if she lost her footing.

*About this much to go,' Gribelin said, spreading his hands the width of a football. *We'll back off and let the proxy dig out the rest.'

*Sifters,' Sibyl said, pointing to two pink plumes on the horizon, sailing slowly from left to right like the smoke from an Old-World ocean liner. *We'd best not hang around.'

The truck and the airship backed off a couple of hundred metres. Gribelin's robot had detached itself from the prow of his vehicle and was now striding across the open terrain. Gribelin had gone into ching bind, otherwise immobile as he drove the proxy to the edge of the hole. It was the same kind of skeletal, minimalist unit that Sunday had chinged on the Moon, constructed from numerous tubes and pistons. It squeezed into the hole effortlessly, folding itself into a tight little knot like a dried-up spider, and vanished down the shaft. A few moments later, gobbets of rubble began to pop out of the opening. If there's a booby trap, Sunday thought, we'd best all pray it isn't nuclear.

But after a few minutes' further excavation, the proxy had unearthed the box. Deeming it to be safe, at least for the moment, Sunday returned to the shaft and looked down. The proxy had extricated itself, allowing her a clear view of the object. About two-thirds of the upright container had been exposed, revealing it to be of dull, anonymous-looking construction. The size of a picnic hamper, the grey alloy casing was scratched and slightly dented. Sunday made out the seam of a lid, and what appeared to be a pair of simple catches in the long side.

She nodded at Gribelin. *Bring it all the way out.'

They retreated again and waited for the proxy to haul the box from the shaft and deposit it on the ground lengthwise, with the lid facing the sky. In all the red emptiness of Mars, it looked like something painted by Salvador Dali: a tombstone in a desert, maybe.

Sunday was the first to reach it. She sent the proxy away, not willing to let anyone else open the lid now that she had come this far. Different on the Moon, when Chama had been the one who had that privilege. Then, she'd barely known what she was getting involved with. Now it was as personal as anything in her universe.

Sunday knelt next to the box. Jitendra was behind her, but the others were still keeping their distance. Let them, she thought as she worked her gloved fingers under the catches and applied pressure. They flipped open obligingly, and Sunday had her first real inkling of disquiet. She'd never been entirely persuaded by Dorcas's argument that a box could not have been under the surface all this time and not be found by the machines. But catches that had been snapped shut sixty or more years ago and then exposed to six decades of Martian cold ought to feel tighter than these.

The lid swung open just as easily. It was only then that Sunday realised she should have considered the possibility that the box had been packed and sealed under normal pressure conditions rather than in the thin air on the face of Mars.

Too late . . . But no: it either hadn't been pressure-sealed, or the air had leaked away over the decades.

She looked inside. The box contained another box: a lacquered black receptacle with a flower pattern worked into its lid. There was just enough room around the outside of the smaller box to get her fingers in. She reached for it.

And felt something touch the back of her head.

*It's not a weapon,' Dorcas said. *We need to be clear about that. I am not holding a weapon against your helmet. I would never do that. What I am doing is holding a non-weapon, a tool, a normal part of our equipment, in such a way that harm could conceivably come to you if I were careless. Which I won't be, provided you do nothing that might . . . distract me.'

Sunday was surprised by how calm her own voice sounded. *What would you like me to do, Dorcas?'

*I'd like you to let go of that box, the smaller one, and step away from the big box. I'm right behind you, and I'm going to stay right behind you.'

Sunday removed her fingers from the gap between the boxes. She'd budged the small box just enough to feel that it was light, if not empty.

*I don't understand what's going on,' she said, standing and moving away from the box as she'd been told to. *Other than the fact that it feels criminal.'

*Not at all,' Dorcas said. *Quite the opposite, really. I'm intervening to prevent the execution of a criminal act. In the absence of an effective Mechanism, I'm obliged to do so. Now kneel again.'

*If there was a Mechanism,' Sunday answered, lowering down as she'd been ordered, *I doubt very much whether you'd be holding something against the back of my helmet.'

*That's as may be. But as I said, what we're trying to do here is stop a crime, not create one.'

*The crime being . . . ?'

*The removal of artefacts from the Evolvarium without the necessary authorisation. I'm afraid everything here that isn't geology belongs to the Overfloater Consortium. You should have realised that before you came blundering in.'

From her kneeling position Sunday looked around slowly, careful not make any sudden movements. She had walked perhaps twenty paces from the big box when Dorcas ordered her to kneel again. The woman was still behind her. Sibyl, the other Overfloater, was holding a kind of pneumatic drill, double-gripped like a gangster-era machine gun. It was heavy and green and wrapped in a gristle of cabling. Gribelin and Jitendra were kneeling on the ground before her, their hands raised as high as their suit articulation allowed.

*Piton-drivers,' Dorcas said. *We use them to fire anchors into the ground when we need to moor-up during a storm. They use compressed air to drive self-locking cleats fifty centimetres into solid rock. Just think what that would do to common-or-garden suit armour.'

*I didn't come to steal from the Overfloaters. You know why I'm here. Whatever's in that box is family property, that's all, and it was buried here before the Evolvarium was created. It's got nothing to do with you or your machines. If I take it, nothing changes. No one gets richer or poorer.'

*If that's the case,' Dorcas said, *then you won't mind if I have it instead, will you?'

*I said it belongs to me, to my family.'

*Can you prove this?'

*Of course. I didn't end up here by accident. I followed clues, all the way from the Moon.'

*Then you can submit a claim for return of confiscated property through the usual channels.' Dorcas seemed to think for a moment. *Of course, to prove that you followed those clues, you'll have to mention that incident with the Chinese, to which your name hasn't hitherto been linked.'

*Who's behind this?' Jitendra asked.

*There's no one "behind" anything,' Dorcas said. *I'm merely asserting the rule of law.'

*It's just that you'd only know about what happened on the Moon if the Pans had told you,' Jitendra said.

*I'm not surprised,' Sunday said. *If anything, I'm amazed it's taken them this long.'

*To do what?' Gribelin asked.

*To steal the box from under my nose. It's been too easy, hasn't it? They've been falling over themselves to help us get this far. Now they've decided: enough is enough. We don't need Sunday to follow the rest of the clues. We can do that on our own, thanks very much, or just not bother.' She shook her head, disgusted at her own unwillingness to see things clearly until this lacerating moment. *Soya warned me,' she said.

*Soya?' Dorcas asked. *Who the hell is Soya?'

*Someone I should have listened to when I had the chance. Not that it would have made much difference. How far could I have got, without the Pans' assistance?'

*Maybe I'm missing something,' Gribelin said, *but if the Pans are paying me, why is this shit happening?'

*Let's not allow this to come between us, Grib,' Dorcas said soothingly. *We're both too old for that. You've done an honest job and you've been paid for it. You had no right to assist in the extraction of materials from the Evolvarium, so you could say that you're getting off very lightly by being interdicted before the crime could be fully actualised.'

*I told you what we had in mind. You said nothing about stealing the fucking box from me at the last minute.'

*Yes, well, that was before I was fully cognisant of the possibilities.'

*When did they contact you?' Sunday asked. *Was it yesterday, after we'd been brought aboard? Was that why you delayed the dig, when we still had daylight to spare? So you could haggle terms with the Pans?'

*She's not going to admit to them being behind this,' Jitendra said.

*No,' Sunday said. *You're right. But I thought they could be trusted a to a point, at least. I trusted Chama and Gleb. I even trusted Holroyd. And if they're screwing me over, what are they doing to my brother?'

*I very much doubt that Chama and Gleb had anything to do with this,' Jitendra said.

On an open channel, obviously not caring that her words would be heard by everyone present, Dorcas said, *The box is secure. Send down two more crew to pick us up and start prepping for departure. I want to be out of here before the golem leads the hammerheads to us.'

*May be a bit late for that,' Gribelin said, angling his helmet to nod eastwards. Still kneeling, Sunday twisted to look as well, keeping her movements smooth and slow. She made out a plume of dust, a bumbling silver glint at the point where it met the ground.

Dorcas cursed, some Martian oath that the translation layer couldn't parse. *I was meant to be alerted!'

*Nine kays and closing,' Sibyl said. *There's still time, if we hurry.'

Dorcas prodded Sunday. *Get up.'

*Make your mind up. You just told me to kneel down.'

This time the prod was harder, enough to rattle Sunday's head against the inside of her helmet. *I won't ask again. Remember, bad things happen out here. No one's going to bat so much as an eyelid if you don't show up in Vishniac again. They went into the Evolvarium without an official escort a what were they expecting?'

Sunday rose. *Whatever you think you're doing, understand this. You're not just stealing this box from me. You're stealing the corporate property of Akinya Space. Are you really sure you want to make an enemy of us?'

*Tell that to Lin Wei. I seem to remember Akinya Space stuck the knife in her business, all those years ago.' A prod, less violent this time. *Now walk. All of you. Go as far as that ridge, and keep close to each other.'

Sunday pushed any thoughts of grand heroics out of her mind. She wasn't going to take a chance against the piton-driver, not when Dorcas was only a few paces behind her. The three of them did as they were instructed, leaving Sibyl free to retrieve the smaller box. Turning to look back while she walked, Sunday watched the other woman extract the lacquered box from the larger container without incident. She held it up to her visor and with one gloved hand eased up the patterned lid.

Sibyl examined the contents for a few seconds, poking a finger into whatever was inside, then closed the lid carefully. There was no way of telling what she'd seen.

*Keep walking,' Dorcas said.

Despite the order, Gribelin stopped and pointed. *Hammerhead!' he bellowed, like a whaler sighting a spout.

*Move!' Dorcas snarled.

The hammerhead was some distance beyond the golem's rover, but it was rearing up now, assuming full and dreadful aspect. Sunday's visor graphed up a high-mag zoom, sensing her focus. A down-angled claw hammer, big as the rover itself, pivoted on the head-end of a mechanical spine as long as a train. The machine cut through the terrain in an S-wave, each of its house-sized spinal modules equipped with out-jutting legs, sinuous and in constant whipping motion. The golem was travelling quickly, kicking dust back at its pursuer, but the hammerhead looked to be gaining. They watched it scoop up boulders and fling them through the air, raining down on the golem with ballistic precision.

Sunday had been running from the golem from the moment it had announced itself in Crommelin, but now she welcomed its arrival. Given the alternative, she would far rather deal with Lucas than Dorcas and the Pans. Watching the hammerhead close the distance on the rover, she willed the golem forward.

It wasn't enough. A car-sized boulder spun through the air, barely missing the rover and landing slightly ahead of it. The rover bludgeoned into the obstacle, its nose digging down as its tail flipped up. Wheels spun in the air. The rover, its front end crumpled, fell onto its side. The hammerhead continued throwing rocks as it approached.

Sunday tore her gaze away from the spectacle long enough to see the airship reaching down its arms to scoop up Dorcas and Sibyl. It hauled them into the sky, along with their improvised weapons and the black box.

*Good luck!' Dorcas said over the suit-to-suit channel. *We'll do what we can to push that hammerhead away, but I wouldn't stick around if I were you.' She let her piton-gun fall to the dust. *I'll buy you a drink next time we're both in Vishniac, Grib.'