SIMI VALLEY, Calif. — You smell it, or think you do. Like a bonfire on a beach. Then you see it in your headlights. Ash. Or maybe insects? The signs are coy at first, on the westbound 118 Freeway, cleaving through sandstone crags that are 70 million years old. The thunderhead of smoke, a purple lesion on the orange twilight, is mysterious but not alarming. But you round a bend near the Santa Susana Pass and the fire is suddenly before you: ruby-red ribbons of flame coiled around dark hills of sagebrush and sumac, accented by the snaking brake lights of Simi Valley traffic. It is unnatural and natural, simultaneously.

This is the Easy Fire, the one that gnawed the perimeter of the Ronald Reagan Presidential Library, and it quickly disappears from sight. It’s nighttime now, and the winding roads and staggered hillsides perform sleights of hand. A wildfire can be hard to find and easy to lose. Hunting for one, you stumble upon another. Farther west in Somis, there is a soft orange glow over a ridge. A sunrise from the north. A newborn wildfire. It’s so new that police officers — mapping evacuations on the hood of a cruiser on East La Loma Avenue — aren’t sure of its name.

It will be christened Maria. Fingers of flame clutch the top of the ridge, then embers cascade over the near side of the canyon. Parts of the hillside resemble erupting volcanoes in miniature. Helicopters roar overhead and unleash curtains of water. The fire stabs west, searing a path toward the Santa Clara River, fueled by hissing Santa Ana winds that drown out the crackle. Trees spasm in the wind, then catch fire. Smoke rolls like a fast-moving fog past Ventura County firefighters on East La Loma.

Capt. Steve Kaufmann is surveying the fire. Unpredictable, he calls it. Erratic. Its movement reminds him of the Thomas or Woolsey fires, which over the past two years burned 600 square miles in the greater Los Angeles area. Humidity’s at 3 percent. Winds are at 30 mph. That means “explosive fire behavior,” Kaufmann says.

If you have nothing at stake but yourself, it’s possible to stand within 100 yards of this wildfire and just watch it. It is an eerie, mesmerizing experience.

If you do have something at stake, you are inside your own little apocalypse. On one side of the street, a farmer and his crew are yanking an industrial hose around, spraying the tree line of the property in a last-ditch attempt to protect his lemon and avocado orchards. On the other side of the street, Alexia Baker, 28, is evacuating alpacas, pigs and horses from her family’s ranch.

She is dressed as a mermaid. It is Halloween.

Baker’s husband and father stay behind to extinguish the trees one by one, using their own water trucks, as firefighting crews encircle homes along East La Loma and begin the defense.

“The fear comes around every year,” Baker says two days later, after the evacuation order is lifted. “It happens between October and November when the winds pick up. And the winds in Somis are unbelievable. They’re hurricane-level winds, every year. And that alone is terrifying for the kids and animals. And us. Each year we get a little better at it. Prior to any wind warnings, I have our cars packed up. It becomes a way of life.”

Living with wildfires

California burns. Always has. Purposefully, in some cases: A thousand years ago, the Sierra Miwok used fire to stimulate grasslands and cultivate acorn production. But often the fire has come unbidden, forcing residents to play defense. In November 1961, Richard M. Nixon, a year after losing the presidency, found himself on the roof of his Brentwood rental home on North Bundy Drive, wearing a dress shirt and tie, hosing down cedar shingles as a wildfire barbecued the hills around him.

At 1:30 a.m. on Oct. 28, in the 1800 block of North Sepulveda Boulevard, high winds knocked a eucalyptus branch into a power line. A couple of white flashes of electricity turned into the Getty Fire. A few hours later, eight houses up from Nixon’s old rental, developer Ramtin Ray Nosrati found an inferno advancing on the palatial lumber frame of his 20,000-square-foot construction project. He had already activated a sprinkler system remotely to douse the property, and credits it with helping to spare the house.

In those moments, Californians can feel in control. Fire, and fate, can be outmaneuvered. “You can’t make an earthquake stop,” Nosrati says. “A hurricane, it’s going to go where it’s going to go. With a fire there’s a lot you can actually do.”

Over the decades, Californians have gotten good at dealing with wildfires. There are brush-clearing regulations and no-parking rules on narrow roads during high-risk weather. In Malibu, mansions get built with underground water cannons that rise to meet a blaze, and residents train to activate hydrants on their streets. Choppers snort water from the surf and dump the Pacific Ocean over the flaming Palisades. Homeowners in Hollywood strip their property of pines and replace them with succulents. Insurance companies dispatch private teams to foam clients’ property lines. Architects and Realtors use terms such as “defensible space” and “fire resilience.”

But the fires still start, and the fires still come, and panicked Angelenos still chuck the good silver into their saltwater pools before fleeing. In the past two years, at least 17,000 wildfires have burned 5,000 square miles of California. Since 1972, the state’s annual burn area has quintupled, which is probably driven by human-caused global warming, according to a research article published in August in the journal Earth’s Future. Large autumn fires will probably become more frequent.

Into this anxious moment comes a man named Jim Moseley, who looks like Richard Dreyfuss from the “What About Bob?” era. Moseley is a trombonist who has played with Frank Sinatra. He is also an entrepreneur who offers a suite of fire protection services, including a spray called SPF3000, which he claims can give your home a fighting chance when other defensive measures have failed. It’s about $4 per square foot of coverage. He has sprayed Neverland Ranch. He has sprayed the home of a “Star Wars” actor, he says. And on Halloween afternoon, another “red flag” day of high fire risk, Moseley paid a visit to writer-actor Bo Svenson, who in “Kill Bill: Volume 1” plays the reverend at the massacre of Uma Thurman’s wedding.

“You have so much fuel around your house,” Moseley told Svenson, whose backyard overlooks a canyon in the Pacific Palisades. There are homes up narrow, twisting roads that have breathtaking views — and driveways that don’t accommodate firetrucks.

“I suspect this hill could be a gold mine for you,” Svenson said in his Swedish baritone, name-checking an Oscar-winning actress with a neighboring abode. “There’s money here. And everyone’s nervous.”

Across the L.A. area, cars are parked facing out. Plastic tubs are loaded with important documents and priceless mementos. Power is cut to thousands of people, to avoid live wires going down in the Santa Ana winds.

Wildfires are happening anyway. The Saddleridge Fire, Oct. 10 in the San Fernando Valley, forced 100,000 people to evacuate. The Tick Fire, Oct. 24 near Santa Clarita, destroyed 24 homes. At a winery in Northern California on Oct. 26, a bride and groom took wedding photos wearing face masks; the orange haze of the Kincade Fire illuminated the vineyard behind them as it consumed 120 square miles of Sonoma County.

In the first minutes of Halloween, at 12:18 a.m., police identified a stolen Dodge Dart traveling on Van Buren Boulevard in Riverside. The driver refused to pull over, led officers on a high-speed chase, crashed into a field and sparked a brushfire. By dawn, the 46 Fire had swallowed more than 200 acres in Jurupa Valley, destroyed three homes and prompted evacuations. It was a man-made fire fueled by scrub like chaparral, which requires fire to germinate and propagate. Unnatural and natural, simultaneously.

This is the dissonance that has settled in Southern California. Schools announce closures on balmy autumn days. Generators hum as residents try to maintain continuity through blackouts. Families become temporary refugees at evacuation centers. Window shoppers catch a whiff of smoke in Beverly Hills.

The 'threshold of control'

“There’s no promises in this life.”

Thirty miles southwest of the 46 Fire, Dean Koontz, the mega­selling novelist, was standing outside his enormous new home the morning after Halloween.

“We had friends who wouldn’t move to California because of earthquakes.”

Like other Californians, he has stood on a roof with a garden hose and a stance of defiance.

“They moved to the Gulf Coast and got hit by a hurricane.”

It costs a fortune to insure some homes in California. This is why Koontz invited Moseley and his team for a consultation about a defensive sprinkler system and his SPF3000 spray. Local authorities have challenged the effectiveness and safety of the product, but Moseley has testimonials from grateful clients and documentation of test results.

He also has his on-the-go demonstration. On Koontz’s front stoop, Moseley blowtorches one end of a piece of wood. It ignites, burns, starts to disintegrate. Then he torches the other side, which has been treated with SPF3000. It blackens but does not ignite. Then Moseley scrapes the charred veneer with a car key to reveal intact wood underneath.

“Impressive,” Koontz says. His Tuscan-style villa is in a gated community near Irvine. This is a place of Bentleys and catering trucks, and an air of invincibility. Koontz knows that nothing is invincible. If he were younger, maybe he’d move to a place that wasn’t quaking and conflagrating so much. Arizona, perhaps. But he loves it here.

“None of us live forever,” he says. “And you have to weigh the quality of life with the risk.”

Southern California is a preposterous paradise, a luxurious dystopia. Over this past month, fire crews made of criminals were released from prison to protect mansions in Brentwood. In Whittier — where you can actually hear the power lines fizz overhead — a brushfire displaced an encampment of homeless people that residents had complained about for months. In recent decades, California has sprawled rapidly into the “wildland-urban interface,” or WUI, where the views are pretty but the ecosystem bridles at our presence.

On Friday afternoon in San Bernardino, a lone firefighter sat in his truck, right in the WUI. In front of Capt. Matt Topoleski was a scorched slope leading up to national forest. Behind him was a house that was totaled by the Hillside Fire. He’d been on the job for 19 days straight, and had just finished mopping up the scene. The shadows were long. The wind kept trying to shut the door to his truck.

“For thousands of years, fires have come down these canyons, long before man,” said Topoleski, 57, his hands sooty. “Now here we are. We’re the intruder.”

California burns. Always has. Topoleski remembers the Panorama Fire in 1980. The Old Fire in 2003. Same hills here. He mentions the “threshold of control,” the point where the capability of a firefighting force meets the power of the fire itself. It’s fire jargon, like wildland-urban interface, but it sounds in this moment like a natural truth. With a fire you can exert some control. You can build a home out of board-form concrete instead of stucco. You can pay for the remote-control sprinkler system. You can take a chance on a spray with a cute name. But there’s no sure thing in the WUI, Topoleski says. He pronounces it “woo-ee.”

“We all want to prosper and appreciate beauty,” Topoleski says as his radio crackles with a bulletin about someone setting off fireworks across town. “You’ve just got to be prepared to leave.”