The eighth book in the Women's Murder Club series

THE OLD CHROME-YELLOW school bus crawled south on Market Street at half past seven that May morning. Its side and back windows were blacked out, and a hip-hop hit throbbed into the low- lying mist that floated like a silk veil between the sun and San Francisco.

Got my ice

Got my smoke

Got my ride

Ain’t got no hope

Hold ya heads up high

Don’t know when

Ya gonna die…

The traffic light changed to yellow at the intersection of Fourth and Market. The stop-sign arm at the driver’s side of the school bus swung out, the four-way hazard lights burned amber, and the vehicle came to a halt.

To the right of the bus was a shopping mall, a huge one: Bloomingdale’s, Nordstrom, the windows papered with large Abercrombie posters of provocative half- naked teens in black and white.

To the left of the bus was a blue Ford van and then one of two islands splitting the road – a staging area for bus passengers and tourists.

Two cars behind the school bus, Louise Lindenmeyer, office manager, late for work, braked her old gray Volvo. She buzzed down her window and glared at that goddamned school bus.

She’d been stuck on its tailpipe since Buena Vista Park, then watched it pull away from her at the light at Fifth and Market as a stream of traffic took the turn and pulled in front of her.

And now that bus had stuck her at a light… again.

Louise heard a shout. “Hey, asshole!”

A man in his shirtsleeves, tie flapping, face bunched up, dried shaving cream under his left ear, walked past her car to give the bus driver hell.

A horn honked, and another, and then a cacophony of horns.

The light was green.

Louise took her foot off the brake and at that instant felt a concussive shock, her ears ringing as she saw the roof of the school bus explode violently upward.

Chunks of burning metal, steel-and-glass shrapnel, shot out in all directions faster than gunfire. A mushroom cloud like that of a small A-bomb formed above the bus, and the box-shaped vehicle became a fireball. Oily smoke colored the air.

Louise saw the blue van in the lane to the left of the bus bloom with flame, then blacken in front of her eyes.

No one got out of the van!

And now the blaze rushed at the silver Camry directly in front of her. The gas tank blew, and fire danced over the car, consuming it in vivid, leaping flames.

The bunch-faced man pulled himself up off the pavement to the hole where her passenger-side window had been. His shirt was gone. His hair was black frizz. The skin of his face was draped over his collarbone like tissue paper.

Louise recoiled in horror, grappled with her door handle as fire lapped at the hood of her Volvo. The car door opened and the heat rushed in.

That’s when she saw the skin of her own arm still on the steering wheel, as if it were a glove turned inside out. Louise couldn’t hear the businessman’s horrified screams or her own. It was as though her ears had been plugged with wax. Her vision was all dancing spots and blurry shapes.

And then she was sucked down into a well of black.

MY PARTNER, RICH CONKLIN, was at the wheel of our unmarked car and I was sugaring my coffee when I felt the concussion.

The dashboard shook. Hot coffee slopped over my hand. I shouted, “What the hell?” A few moments later the radio sputtered, the dispatcher calling out, “Reports of an explosion at Market and Fourth. Nearby units identify and respond.”

I dumped my coffee out the window, grabbed the mic, and told Dispatch we were two blocks away as Conklin accelerated up the hill, then braked so that our car slewed across Fourth Street, blocking traffic.

We bolted from the car, Conklin yelling, “Lindsay, watch out. There could be secondary explosions!”

The air was opaque with roiling smoke, rank with burning rubber, plastic, and human flesh. I stopped running, wiped my sleeve across my stinging eyes, and fought against my gag reflex. I took in the hellish scene – and my hair literally lifted away from the back of my neck.

Market Street is a major artery. It should have been pulsing with commuter traffic, but instead it looked like Baghdad after a suicide bomb. People were screaming, running in circles, blinded by panic and a screen of smoky haze.

I called Chief Tracchio, reported that I was the first officer on the scene.

“What’s happening, Sergeant?”

I told him what I saw: five dead on the street, two more at the bus stop. “Unknown number of victims alive or dead, still in their cars,” I coughed into the phone.

“You okay, Boxer?”

“Yes, sir.”

I signed off as cruisers, fire rigs, and EMS units, their sirens whooping, streamed onto Market and formed a perimeter at Third and at Fifth, blocking off oncoming traffic. Moments later, the command vehicle rolled up, and the bomb squad, covered top to toe in gray protective suits, poured onto the debris field.

A bloodied woman of indeterminate age and race staggered toward me. I caught her as her knees buckled, and Conklin and I helped her to a gurney.

“I saw it,” the victim whispered. She pointed to a blackened hulk at the intersection. “That school bus was a bomb.”

“A school bus? Please, God, not kids!”

I looked everywhere but saw no children.

Had they all been burned alive?

WATER STREAMED from fire hoses, dousing flame. Metal sizzled and the air turned rancid.

I found Chuck Hanni, arson investigator and explosion expert, stooping outside the school bus’s side door. He had his hair slicked back, and he wore khakis and a denim shirt, sleeves rolled up, showing the old burn scar that ran from the base of his right thumb to his elbow.

Hanni looked up, said, “God-awful disaster, Lindsay.”

He walked me through what he called a “catastrophic explosion,” showed me the two adult-size “crispy critters” curled between the double row of seats near the driver’s side. Pointed out that the bus’s front tires were full of air, the back tires, flat.

“The explosion started in the rear, not the engine compartment. And I found this.”

Hanni indicated rounded pieces of glass, conduction tubes, and blue plastic shards melted into a mass behind the bus door.

“Imagine the explosive force,” he said, pointing to a metal projectile embedded in the wall. “That’s a triple beam balance,” he said, “and I’m guessing the blue plastic is from a cooler. Only took a few gallons of ether and a spark to do all this…”

A wave of his hand to indicate the three blocks of utter destruction.

I heard hacking coughs and boots crunching on glass. Conklin, his six-foot-two frame materializing out of the haze. “There’s something you guys should see before the bomb squad throws us outta here.”

Hanni and I followed Conklin across the intersection to where a man’s body lay folded up against a lamppost.

Conklin said, “A witness saw this guy fly out of the bus’s windshield when it blew.”

The dead man was Hispanic, his face sliced up, his hair in dyed-red twists matted with blood, his body barely covered in the remnants of an electric-blue sweatshirt and jeans, his skull bashed in from his collision with the lamppost. From the age lines in his face, I guessed this man had lived a hard forty years. I dug his wallet out of his hip pocket, opened it to his driver’s license.