For unsuspecting residents of a suburban Montclair, New Jersey, neighborhood, it seemed too crazy to be believed: their quiet, unassuming neighbors had turned out to be Russian spies.

The couple, known as Richard and Cynthia Murphy, had appeared to be part of a typical American family, living in a beige, two-story colonial-style home with their two young daughters at 31 Marquette Road.

Cynthia’s business card said she worked as a financial planner at an accounting company in nearby Manhattan. Richard told neighbors he was a stay-at-home dad raising Lisa, age nine, and her 11-year-old sister, Kate.

The shocking truth emerged when the FBI raided the house in 2010: Richard and Cynthia’s real names were Vladimir and Lydia Guryev.

“You could have told me they were Martians from space and I would have been less surprised,” said Elizabeth Lapin, a poetry professor who still lives down the street from the home now known as “the spy house.”

The Guryevs had been gathering information since the 1990s for Russia’s SVR, which the FBI describes as the modern equivalent of the KGB. The KGB, if you remember, was the widely feared national security agency of the now-defunct Soviet Union, tasked during the Cold War with running a domestic secret police force and operating a network of spies throughout the world.

On June 27, 2010, the FBI arrested the Guryevs along with eight other alleged Russian spies in Manhattan, Yonkers, Boston and northern Virginia. The announcement triggered headlines reminiscent of the Cold War, and even inspired the creation of FX’s 1980s-era spy drama “The Americans.”

But while the deep-cover Russian spies on “The Americans” “do all sorts of reckless, wild things,” said neighbor Virginia Bailey, that wasn’t the impression she got from the Guryevs.

“By all accounts,” Bailey told CNN, “these neighbors were neither reckless nor wild.”

This is what it was really like to live next door to a Russian spy, according to various Montclair residents who spoke to CNN.

Hiding in plain sight

Looking back, neighbors say the Guryevs’ “spy house” was a perfect place to hide in plain sight. Manhattan was just 30 minutes away by shuttle bus. And the house property backed up against a 21-acre wildlife preserve where meetings with agents and exchanges of information could easily be hidden from prying eyes.

The family wasn’t overly social — but they weren’t exactly hiding either. Neighbors say they sometimes attended summer neighborhood block parties.

Before the raid, Bailey and her daughter, Jessie Gugig, remember seeing their neighbor “Cynthia” walking her dog many mornings down Marquette Road. Although they never stopped to have a conversation, Bailey remembered her as being “very attractive and very well put together. She always dressed very nicely.”

Some neighbors said the couple spoke with accents, but Lapin said she never heard one.

“The girls built a lemonade stand one summer,” Lapin said. “That was such an American thing.”

Lapin said she had a “premonition” that “something strange” was going on long before the raid. A few months before, she noticed unusual, prolonged construction under the neighborhood streets. The Friday before the raid, she said a police car had been parked in front of her house.

But espionage? It never occurred to her, Lapin said.

How they got caught

The FBI and CIA first learned about the collection of deep-cover SVR spies in the United States in the early 2000s. They were living as so-called “illegals,” meaning they had no diplomatic protection.

US authorities secretly surveilled all the spies for years, bugging the Guryevs’ house and even secretly searching it when they weren’t around. The FBI told CNN’s original series “Declassifed” that the Guryevs tried so hard to blend into American society that they didn’t even speak Russian inside their own home.

Eventually, the United States cracked a secret code the spies used to communicate with Moscow, allowing the FBI to learn more about the Guryevs’ comings and goings. In 2009, the FBI shot video of a meeting between Vladimir and a Russian government official. Authorities decided it was time to arrest the spy ring.

Jessie Gugig remembers being a 15-year-old experiencing the shock of watching FBI vans stop at the Guryevs’ home, just a stone’s throw from her own residence.

“Eventually another car pulled up and guys in suits with earpieces showed up with some papers that must have been a warrant,” Gugig, now a 22-year-old law student, recalled. Agents suddenly poured into the home, turning on the lights and searching it from top to bottom.

“The house got lit up like it was Christmas,” she said.

For at least a week after the raid, the press seemed to be everywhere throughout the neighborhood, said Gugig’s mother Bailey. “I mean hordes of them,” she said. “It was just a carnival.”

Lapin gathered up enough courage to approach the house after the arrest and peer into the window. Inside she saw several items on a table — including Lisa’s textbook on Chinese grammar, stacks of coins and a copy of a 1953 post-World War-II memoir, “Woman in Berlin.”

On the wall next to a piano was a “beautiful painting” of a young girl, which Lapin believes was a self-portrait by Kate.

The Guryevs’ two girls, Bailey said, were taken away to stay with a family friend.

What happened to the kids?

Two weeks after the FBI arrests, Moscow and Washington made a deal.

After all ten of those arrested pleaded guilty to being Russian agents, the United States agreed to transfer them to Russian custody. In exchange, Moscow agreed to release “four individuals” who were “incarcerated in Russia for alleged contact with Western intelligence agencies,” the Justice Department said.

Kate and Lisa — who were born in the United States — eventually accompanied their parents back to Russia. US Attorney General Eric Holder told CBS’ “Face the Nation” in 2010 that the Guryevs’ kids and all other children of the Russian agents were “repatriated.”

“That whole aspect was very sad,” said Bailey. “To all of a sudden have their lives completely and utterly changed. The children didn’t know Russia … They have to leave their friends abruptly and suddenly. … Everything would have just been so radically different.”

Former FBI operative Eric O’Neill, who helped catch FBI double agent Robert Hanssen, said in 2010 that it’s unusual for spies serving overseas to have children, because they could suffer from divided loyalties.

“When you’re a parent, you’re supposed to take care of your kids. You are supposed to put them first in your life. And a spy can’t do that,” O’Neill said.

Are other spies still living among us?

At the time, having Russian spies in the neighborhood felt like a weird throwback to the Cold War, neighbors said.

But now that people on Marquette Road are hearing more about heightened tensions between Russia and the United States, they say the idea of Russian spies living among Americans doesn’t seem so surprising. Some of them are following the current US government investigations into Russia’s meddling in the 2016 election and potential collusion with members of Donald Trump’s presidential campaign.

In fact, Russian spies are ramping up their intelligence-gathering efforts inside the United States, current and former US intelligence officials told CNN this month.

Former Soviet KGB spymaster Oleg Kalugin told CNN he “would not be surprised” to learn that Russia is still running illegal deep-cover spies in the United States. But he suspects these programs would be less active now than in 2010. Kalugin, who says he never ran illegal deep-cover programs, criticized them as wasteful and inefficient.

“It’s risky and lonely and a really difficult job,” he said.

One of the key pieces of evidence uncovered by the FBI in the 2010 case was a message Russian spymasters sent the Guryevs shortly before their arrest.

“You were sent to USA for long-term service trip,” the message said. “Your education, bank accounts, car, house etc. — all these serve one goal: fulfill your main mission, i.e. to search and develop ties in policymaking circles and send intels to C.”

“C” is thought to refer to “The Center,” an espionage information clearinghouse in Russia.

What’s next for the ‘spy house’

Built in 1950, the beige, two-story house is a typical middle class home for the area. It measures a bit more than 1,800 square feet and the county valued it this year at $425,700, according to Essex County tax records.

So much time has passed that “it’s hard to believe it happened,” said Bailey.

“Nature is kind of taking the house back,” Gugig said. “Ivy is starting to eat into the house. The garden is completely overgrown.”

“The house just sits there and it’s empty,” she added. “It’s just a constant reminder.”

Lapin — who has lived near the house for 11 years — said the neighborhood was friendlier before the raid. “I liked the neighborhood — until this event happened,” she said.

But the old vibe has slowly been coming back, she said. Several of her neighbors have left since the raid — replaced by new residents who don’t associate the house with the spies.

A local realtor said the home has recently been sold.

Perhaps a new family will move in soon, which will help Montclair close the book and move on from its connection to international espionage.