She ran toward it, the metal shaft over her shoulder like a javelin. The beast reared back on six of its legs, the other two waving in front of it to ward her off.

From a few yards away she threw the weapon, which burst into light even as it left her hand, wailing through the air with the shriek of a Roman candle. The metal buried itself in the spider, tearing a gash in the mottled flesh. Blue fire spewed from the wound.

The thing screamed hideously, its bloated body crashing to the ground as its arms waved uselessly in the air.

“Oh, bleah!” cried Dess. She stumbled back from the spider, putting one hand over her mouth.

Seconds later a horrible smell washed across Rex and Melissa, dead rat and burned plastic mixed together with rotten eggs. Melissa coughed and gagged, falling to one knee.

“Run for the pit!” Rex managed to cry. They were no more than a hundred yards away.

He ran toward one side of the shuddering spider, still clutching the bag of metal bits. Melissa stumbled after him. Dess dashed past the tarantula, whose legs still flailed wildly, heading for the blue arc of the snake pit.

As Rex ran, the desert before him seemed to be moving, dark sand flowing across his path. The huge spider was sagging, deflating like a punctured balloon.

“Stop, Rex!” Melissa cried, pulling him to a halt. “It’s not dead. Just—”

She didn’t finish, choking on the stench.

Now Rex could see them. Things were pouring from the darkling’s wound, gushing out in a torrent. More spiders, thousands of them. They swarmed in a black river between the two of them and the snake pit.

Dess was on the other side, still running, only a few seconds from the safety of the still flickering lightning. Rex saw her cross the boundary, falling into Jessica’s and Jonathan’s arms.

The black river of spiders changed course, flowing toward him and Melissa. It made a harsh roaring sound as it moved, like a truckload of gravel being poured onto a sheet of glass.

Rex emptied the rest of the bag of metal pieces, scattering its contents in a rough circle around their feet, a couple of yards across. The crawling host swept up to the patch of glittering steel and broke against it, flowing around them like water.

In seconds they were surrounded, an island in a writhing sea of spiders.

The bits of metal sparked and sputtered, the outermost pieces glowing bright purple. A few spiders dared to move into the steel. They burst into flame, but more came, crawling across the bridge of burned bodies.

“How long do you think the steel will last?” he asked Melissa.

“Doesn’t matter,” she said. She was looking upward. Rex followed her dumbstruck gaze.

The other two darklings were coming down.