Just how desperate some of these people are getting is something Mattison discovers when the truck's erratic route around the various obstacles takes it through a badly messed-up segment of a barrio somewhere between Azusa and Covina and they see some kind of pagan religious sacrifice under way in the middle of a four-way intersection, where the pavement has begun to bulge slightly and show signs of imminent buckling as gas pressure builds from below. Flat slabs of blue-black lava have been piled up in the crosswalk to form a sort of rough, ragged-edged altar that has been surrounded by green boughs torn from nearby trees.

  What is evidently a priest -- but not any sort of Catholic priest; his dark face is painted with green and red stripes and he is wearing a brilliant Aztec-looking costume, bright feathers and strips of fur all over it -- is standing atop the altar, grasping a gleaming butcher-knife in his hand. The altar is stained with blood, and more is about to be added to it, because two other men in less gaudy outfits than the priest's are at his side, holding forth to him a wildly fluttering chicken. Assorted pigs, sheep, and birds are lined up back of the altar, waiting their turn. In a wider circle around the site are perhaps fifty shabbily dressed men, women, and children, silent, stony-faced, holding hands and slowly, rhythmically stamping their feet.

  What is taking place here is utterly obvious right away to everyone aboard the Citizens Service House truck. Even so, it isn't always easy to believe the evidence of your eyes when you see something like this. Mattison stares in shock and disbelief, wondering whether they have slipped through some time-fault and have dropped down into an ancient era, primitive and barbaric. But no, no, prosaic evidence of the modern century can be seen on every side, lampposts, store fronts, billboards. It's just what's going on in the middle of the street that is so exceedingly strange.

  "Holy fucking shit," Buck Randegger says. He's a former highway construction worker who has been substance-free about four months and is still plenty rough around the edges. "I thought the fucking Mexicans in this town were supposed to be Christians, for Christ's sake."

  "We are," Annette Perez tells him icily. "And also other things, when we have to be. Sometimes both at the same time." The butcher-knife descends in a fierce arc, the newly headless chicken flaps its wings insanely, the crowd of worshippers jumps up and down and cries out three times in a high-pitched ecstatic way, and Randegger expresses his disgust and amazement at the whole weird pagan scene with a maximum of pungency and a minimum of political correctness. For a moment it looks as though Perez is going to jump at him, and Mattison gets ready to intervene, but she simply shoots Randegger a black glare and says, "If this was your neighborhood, _carajo_, and you had a god, wouldn't you want to ask him to stop this shit?"

  "With pigs? With sheep?"

  "With whatever would do it," she says.

  Gibbons, meanwhile, is backing the truck out of the intersection, since the assembled congregation now is staring at them as though their presence here is quite unwelcome and it seems manifestly not a good idea to try to drive any closer. Mattison, taking one last look over his shoulder, sees a small pig being led up the side of the altar. The truck, still going backward, swings left at the first corner, then takes the next right and right again, which brings it around to the far side of the site of the ceremony in the same moment as a little earthquake goes rippling through the vicinity, 3.5 or so, just enough to make the gaunt blackened palm trees that line the street start swaying. The worshippers in the intersection behind them point at the truck as it reappears, and begin to scream and yell furiously and shake their fists, and then Mattison hears some popping sounds.

  "Hit the gas," he tells Gibbons over his suit radio. "They're shooting at us."

  Gibbons speeds up. The street ahead is carpeted with a layer of loose ash maybe two feet deep, but Gibbons ploughs through it anyway, sending up swirling black clouds that make everybody on the open deck close the faceplates of their suits in a hurry. Beyond the ash is a stretch of crunchy cinders and other sorts of tephra, so that they all grab hold of each other and hang on tight as the truck clanks and jounces onward, and then a little newly congealed lava in the road makes the ride even rougher; but after that the street turns normal again for a while and they can relax, as much relaxation as may be possible while you ride in an open truck through territory that no longer looks like just a suburb of Hell, but the Devil's own back yard.

  There have been repeated outbreaks of tectonic activity here before, early on in the crisis -- that much is obvious from the burned-out houses and the black crusts of old lava everywhere and the ashen landscape -- but something new and big is apparently getting ready to happen. The sky here is dead white from thick upwellings of steam and sulfurous fumes, except where the fumes are coaly black. Streaks of lightning keep jumping around and the ground trembles continuously, as if a non-stop earthquake is going on. The sidewalks are warped and bulging in many places and some little red tongues of lava can be seen beginning to ooze from cracks in the pavement. Every few minutes a dull distant boom can be heard, a muffled sound that definitely gets your attention, something like the fart of a dinosaur that might be sauntering around a few blocks away.

  Three or four weary-looking fire crews are slowly taking up positions in the street and getting their gear into order; some of the biggest pumps Mattison has ever seen have already been hauled into place for the lava-cooling work; police helicopters are whirling overhead, booming down orders to whatever remaining population may still be living here to evacuate the area at once. It is a truly precarious scene. Mattison is ever so happy that he traded the horrors of substance abuse for the privilege of visiting places like this.

  The same thing is occurring to some of his companions, evidently. Blazes McFlynn lays his hand on Mattison's right arm and says, "I didn't sign on for any goddamned suicide missions, Matty. Let me off this fucking truck right now."

  "Let you off?" Mattison says mildly.

  "Fucking A. I want out, this very minute."

  Mattison sighs. McFlynn always makes trouble, sooner or later: if only he had known that this San Dimas operation was going to be tacked on to the day's outing, he probably would have opted to leave McFlynn behind at the outset. McFlynn is, of all goofy things, a bombed-out circus acrobat and pensioned-off movie stunt man, strong as a tow-truck winch, who over the course of time has found relief from stress in a whole smorgasbord of addictive substances and now, having very badly broken his leg while winning a moronic barroom bet that involved jumping off the top of a building and developed a severe limp that makes it hard for him to practice either of his professions, draws generous compensation pay from a variety of sources while undergoing one of his periodic spells of detoxification and Citizens Service. His first name is actually Gerard, but if you call him anything but Blazes he will react unpleasantly. He is the only man in the house for whom Mattison would feel any reticence about decking, for McFlynn, though five inches shorter than Mattison, is probably just about as dangerous in a fight, gimpy leg and all.

  "Are you saying," Mattison asks him once more, "that you don't want to take part in the current operation?"

  "The whole street is going to blow any minute."

  "Maybe so. That's why we're here, to get things under control if it does. You want to walk back from here to Silver Lake? You think you'll catch a bus, maybe, or phone for a cab? The option of your departing this operation simply does not exist at this moment, okay, McFlynn?" McFlynn tries to say something, but Mattison talks right over him, although keeping his voice mild, mild, mild, as he is has been taught to do all the time when addressing the inmates, no matter what the provocation. "You find this work not to your liking, well, when you get your cowardly ass back to the house tonight you can tell Donna that you don't want to do volcano work any more, and she'll take you off the list. You aren't any fucking prisoner, you understand? You don't have to do this stuff against your will and in fact you are perfectly free, if you like, to pack up and leave the house tomorrow and go back to your favorite substance, for that matter. But not today. Today you work for me, and we work in San Dimas."

  McFlynn, who surely was aware when he began complaining that this was where the discussion was going to end, is just starting to crank up a disgruntled and obscene capitulation when Gibbons says, over the radio from the truck cab, "Volcano Central wants us to start setting up the pump, Matty. Satellite scan says there's a lava bulge about to blow two blocks east of us down Bonita Avenue, which is the big street straight in front of us, and we're supposed to dam it up as soon as it comes our way." So they are going to be right on the front line, this time. Fine, Mattison thinks. Hot diggety damn.

  * * * *

  They all get off the truck, and seal up their suits, and set about getting ready to deal with the oncoming eruption.

  Because the pump they will be using this time is a jumbo job, just about the biggest one Mattison has ever worked with, he designates not only Prochaska and Hawks, once again, for the pumping crew, but also Clyde Snow and Blazes McFlynn, who will be up front not only because he's strong but also because Mattison wants to keep a close eye on him. In any case he's going to need all the muscle-power he can get when it becomes necessary to swing that big rig around to keep the shifting lava penned up. He puts the generally reliable Paul Foust in charge of the controls that operate the pump itself. The rest -- Randegger, Herzog, Evans, and the three women, Doheny and Perez and Gulliver -- Mattison deploys at various points along the line to the standpipe, so that they can keep the hose from getting tangled and cope with any other interruptions to the flow of water that might arise.

  Everybody is in place none too soon. Because just as the signal arrives from the rear that the water connection has been made, there comes an all too familiar bellowing and groaning from the next block, as though a giant with a bad bellyache is about to cut loose, and then Mattison hears five sharp heavy grunts in succession, oof oof oof oof oof, followed by an eerie crackling sound, and suddenly the air is full of fire.

  It's like one of the Yellowstone geysers, except that what is being flung up is a lot of tiny bits of hot lava, riding on a plume of bluish steam, and for a couple of moments it's impossible to see more than a few feet in front of your face-plate. Then there is one single booming sound, not muffled at all but sharp and hard, and the bluish geyser of steam in front of them triples or quadruples in height in about half a second, and the pavement ripples beneath their feet as though an earthquake has happened precisely in this spot. Mattison comprehends that there has been a terrific explosion a very short way down the block and they are all about to be hurled sky-high, or maybe are already on their way up to the stratosphere and just haven't had time to react yet.

  But they aren't. What has happened is that an underground gas pocket has blown its head off, yes, but it has done it in one single clean _whoosh_ and all the pent-up junk that is being released has taken off for Mars in a coherent unit, the steam and mud and lava bits and whatnot rising straight up and vanishing, clearing the air beautifully behind it. A couple of good-sized lava bombs go soaring past them, fizzing like fireworks, and come down with thick plopping thunks somewhere not far away, but don't seem to do any damage; and then things are quiet, pretty much. The whole blurry geyser that was spewing straight up in front of them is gone, the ground they are standing on is still intact, and they can see again.

  Mattison has just about enough time to realize that he has survived the explosion when he registers the force of an inrush of cool air that's swooping in from all sides to fill the gap where the geyser had been. It isn't strong enough to knock anybody down, but it does make you want to brace yourself pretty good.

  And then comes the heat; and after it, the lava flow.

  The heat is awesome. Mattison's suit catches most of it, but enough of the surge gets through his insulation so that he has no doubt at all about its intensity. It is what he calls first-rush heat: the subterranean magma mass has been cooking whatever deposits of air have surrounded it down there, and all that hot air, having had noplace to go, has gone on getting hotter and hotter. Now it all comes gleefully zooming out at once. Mattison recoils involuntarily as though he has been belted by an invisible fist, steadies himself, straightens up, looks around to check up on his companions. They're all okay.

  The lava, having busted through the pavement at last, follows right on the heels of that hot blast. A glowing red-orange river of it, maybe two or three feet deep, flowing down the middle of the street, taking the line of least resistance between the buildings as it heads in their direction.

  "Hose!" Mattison yells. "Pump! Hit it, you bozos, hit it right down front!"

  The lava is moving faster than Mattison would prefer, but not so fast that they need to retreat, at least not yet. It's actually three separate streams, each runnel six to eight feet wide, traveling in parallel paths and occasionally overlapping in a braided flow before separating again. The surface of each flow is fairly viscous from its exposure to the cool air, darker than what is below and showing irregular bulges and lobes and puckerings, which break open now and then to reveal the bright red stuff that lies just below. Here and there, narrow tongues of dark congealed lava rise above the stream at sharp angles like sleek fins, making it seem as though lava sharks are swimming swiftly downstream through the fiery torrent.

  As the water from their big hose hits the first onrush of the flow, a scum of cooling lava starts to form almost instantly atop the middle stream. The front of it begins to change color and texture, thickening and turning gray and wrinkled, like an elephant's hide.

  "That's it!" Mattison tells his men. "Keep hitting it there! Smack in the middle, guys!"

  The water boils right off, naturally, and within moments they are able to see nothing in front of them once again except a wall of steam. This is the most dangerous moment, Mattison knows: if the lava, pushed toward them by whatever giant fist of gas is shoving it from below, should suddenly increase its uptake velocity, he and his whole team could be engulfed by it before they knew what was happening to them. For the next few minutes they'll be fighting blind against the oncoming lava flow, with nothing to guide them about its speed and position but Mattison's own perceptions of fluctuations in its heat.

  The heat, at the moment, is really something. Not as fierce as it had been in the first instant of the breakout, no, but powerful enough to tax the cooling systems of their lava suits practically to their limits. It feels like a solid wall, that heat: Mattison imagines that if he leaned forward against it, it would hold him up. But he knows that it won't; and he knows, also, that if things get much hotter they will have to back off.

  What he is trying to do is to build log-shaped strips of solidified lava along the front of the row, perpendicular to the line of movement. These will slow its advance as the fresh stuff piles up behind them. Then he can raise the angle of the hoses and start pumping the water upward to form larger blocks of lava, which he will eventually link to create his dam. And in time he will have buried the live lava at its source, entombing it beneath a little mountain of newly created rock and thus throttling the upwelling altogether.

  The theory is a nice one. But in practice there usually are problems, because the lava, unlike your average river, tends to advance at a variable speed from moment to moment, and you can build a lovely little log-jam or even some good-sized retainer blocks and nevertheless a sudden fast-moving spurt of molten stuff will spill right over the top and head your way, and there is nothing you can do then but drop your hoses and run like hell, hoping that the lava isn't traveling faster than you are.

  Or else, as Mattison knows all too well, your dam will work very effectively to halt the lava in its present path -- thereby inducing it to take up a different path that will send it rolling off toward some still undamaged freeway or still unruined houses, or maybe pouring down a hillside into another community entirely. When you see something like that happening, you need to move your whole operation around at a 90-degree angle to itself and start building a second dam, not so easy to do when you are operating with two-ton pumps.

  Here, just now, everything is going sweetly so far. It's a tough business because of the extreme heat, but they are holding their own and even managing to achieve something. They have been able to maintain themselves at a distance of about half a block from the front edge of the lava flow without the need to retreat, and Mattison can see, whenever the steam thins out a bit, that the color of the lava along the edge is beginning to turn from gray to a comforting black, the black of solid basalt. A pump crew from some other Citizens Service House has arrived, Mattison has been told, and is building a second lava dam on the opposite side of the breakout. The fire crews are at work in the adjacent blocks, hosing down the structures that were ignited by the initial geyser of lava fragments.

  If visibility stays good, if the water supply holds out, if the pump doesn't break down, if the lava doesn't pull any velocity surprises, if some randomly escaping gobbet of hot rock doesn't go flying through the air and melt one of the hoses, if there isn't some new eruption right under their feet, or maybe an earthquake, if this, if that -- well, then, maybe they'll be able to knock off in another hour or two and head back to the house for some well-earned rest.

  Maybe.

  But things are beginning to change a little, now. The lava is penned up nicely in the middle but the bulk of the flow has shifted to the right-hand stream and that one is gaining in depth and velocity. That brings up the ugly possibility that Mattison's dam is achieving diversion instead of containment, and is about to send the entire flow, which has been traveling thus far from west to east, off in a southerly direction.

  Volcano Central is monitoring the whole thing by satellite, and somebody up there calls the problem to Mattison's attention via his suit radio about a fifteenth of a second after he discovers it for himself. "Start moving your equipment to the right side of your dam," Volcano Central says. "There's danger now that the lava will start rolling south down San Dimas Avenue into Bonelli County Park, where it'll take out the Puddingstone Reservoir, and maybe keep on going south until it cuts the San Bernardino Freeway in half on the far side of the park. A piece of the 210 Freeway will also be at risk down there."