Hollywood movies are rampant with stories that paint spies, double-agents and double-crossing frenemies in a heroic light.
But when it comes to the real world and the reality of secret missions, it's a chilling thought.
Picture your next door neighbour, who waves at you every Wednesday whilst putting the bins out, who's picked your kids up from school and with whom you've shared a joke over the garden fence.
Now imagine that they're secretly part of a Russian spy ring, purposely using their suburban ties to infiltrate society and gather information for Moscow to use to its advantage.
It sounds unbelievable, like something plucked from those Hollywood films, but this is exactly what happened in America during the 90s.
Get the news you want straight to your inbox. Sign up for a Mirror newsletter here
A group of 10 deep-cover Russian agents had assumed fake identities to enter the United States and settle themselves in some of the country's most secure and well-to-do neighbourhoods.
It was not uncommon for these 'illegals' to have children together after such extended time, which set them up perfectly as a faux American family.
Richard and Cynthia Murphy, who moved to New Jersey in the mid 90s, did exactly that.
After years of training at notorious Russian spy school ‘The Institute’, Vladimir and Lidiya Guryev (who used the names Richard and Cynthia for cover) were dispatched to the US.
Together, they fooled their neighbours and colleagues for nearly 20 years, and had two children Kate and Lisa, during that time - before their true identity was revealed, and .
According to court documents, Cynthia, the bread-winner in the fake all-American family, was assigned with collecting information on Columbia University faculty whilst she studied there as a student.
This included those who applies to, or were already hired by, the CIA.
After graduation, she worked for the Manhattan accounting firm Morea Financial Services, reportedly earning an annual salary of $135,000 (£108,000)
She also supervised the finances of venture capitalist and philanthropist Alan Patricof, a top fundraiser for Bill and Hillary Clinton.
In 2010, the FBI moved in to make their arrest.
At the same time, eight other members of the spy ring were also arrested as part of the Illegals Program.
The couple, along with the sleeper spies, were swapped by the U.S. for double-agent Sergei Skripal and three other Russian nationals who'd been imprisoned, three of them for espionage.
Richard and Cynthia's children were reunited with their parents in Russia, but are free to return and live in America if they choose.
One of the more famous agents, Anna Chapman, known for her vivid red hair, was thought to have come close to 'honey-potting', or seducing, a member of former President Barack Obama's cabinet which then prompted the FBI to make their arrests.
But the federal agency rebuked these claims, which inevitably turned eyes towards Cynthia and her close ties with friend of the Clinton family, Alan Patricof.
Anna, who is now a model and TV personality back in Russia, is hailed as a national hero.
