Court papers setting out the allegations against 10 people arrested on suspicion of spying for the Russian government reveal details worthy of a Cold War spy novel.
The espionage ring was allegedly trained by the Russian Foreign Intelligence Service (SVR), whose headquarters are known as Moscow Centre.
Its methods are said to have ranged from the hi-tech, such as using private wifi networks to swap data between laptops, to old-school, such as digging up money buried in parks and arranging passwords to use at surreptitious rendezvous.
'THE MISSION FROM MOSCOW'
The court papers say a decrypted message sent from Moscow Centre to two of the accused in 2009 sets out their mission in the US.
"You were sent to USA for long-term service trip. Your education, bank accounts, car, house etc - all these serve one goal: fulfil your main missions, ie to search and develop ties in policymaking circles in US and send intels [intelligence reports] to Center."
The suspects communicated with their Russian handlers using private wireless networks, the court papers say.
One, Anna Chapman, is accused of sitting in a Manhattan coffee shop in January and using a laptop to transfer data to a Russian government official as he passed by in a people-carrier.
"Law enforcement agents utilized a commercially available tool that can detect the presence of wireless networks. The agents detected the presence of a particular network (the "ad hoc network") with two associated (Media Access Control) addresses." Those addresses are believed to be those of Ms Chapman and the Russian, the papers say.
In March, the documents allege, Ms Chapman pulled a laptop out of her bag while in a Manhattan book shop. Meanwhile, a Russian government official was spotted across the street carrying a briefcase. He remained near the shop - without entering - for about 20 minutes. Again, an "ad hoc network" was detected by agents.
A second suspect, Mikhail Semenko, is accused of using his laptop while in a restaurant to link up with a Russian official parked in the car park outside.
CLANDESTINE MEETINGS AND PASSWORDS
According to the court papers, Ms Chapman was briefed in New York by an undercover agent, posing as a Russian consulate worker, to pass a fake passport to another female spy.
The undercover agent explains that the woman "will tell you 'Excuse me, but haven't we met in California last year?' And you will say to her, 'No, I think it was the Hamptons.'" Ms Chapman was then to hand over the passport. But, the papers note, she did not make the rendezvous.
On 26 June 2010, the court documents say, an undercover agent phoned Mikhail Semenko and says: "Could we have met in Beijing in 2004?" Mr Semenko responds: "Yes, we might have, but I believe it was in Harbin."
The documents say a rendezvous on a street corner in Washington DC was set up and, when the two met, Mr Semenko was given a folded newspaper containing $5,000 in an envelope and told to leave it on the following day in a park in nearby Arlington, Virginia. FBI footage from a hidden camera allegedly recorded him leaving the newspaper with cash in the allotted spot.
Intercepted messages from January 2010 also set out how suspect Richard Murphy will recognise an SVR agent in Rome from whom he is to get a fake Irish passport. He is primed to use the phrase: "Excuse me, could we have met in Malta in 1999?" and look for the way his contact is holding a copy of Time magazine.
Some of the suspects are accused of using steganography - a method of concealing data in an image using special software - to pass information to Moscow Centre by posting pictures on public websites.
Using data and a 27-character password gained by searching a New Jersey property in 2005, US agents accessed a steganography programme that led them to websites where they found certain images, the court documents say.
"These images appear wholly unremarkable to the naked eye. But these images (and others) have been analysed using the steganography program. As a result of this analysis, some of the images have been revealed as containing readable text files."
The suspects are accused of using short-wave radios to send and receive "radiograms" - coded bursts of data - to Moscow Centre. US agents believe they are referred to as "RG"s by the alleged spies.
Decoded electronic messages sent using steganography include one from Moscow Centre in 2009 saying: "Pls, make sure your radioequipment [sic] for RG rcptn is in order. We plan to send a couple of test Rgs [.]"
A search of a Seattle apartment linked to the suspects in 2006 turned up short-wave radio equipment. "In addition, agents observed and photographed spiral notebooks, some pages of which contain apparently random columns of numbers," the court papers say.
Those numbers are believed by US agents to be codes for deciphering incoming radiograms.
MONEY FROM MOSCOW?
The suspects are said to have brought back bundles of cash from abroad into the US.
Two of the suspects, Vicky Pelaez and Juan Lazaro, are recorded apparently counting out a large sum of money after she returned from a Latin American country in 2003. Ms Pelaez says she has eight bags of "10" - interpreted as meaning eight bags containing $10,000 each.
In 2007, Mr Lazaro is filmed allegedly meeting a Russian government official in a park in the same Latin American country. Court papers say the footage "captured, among other things: the two men walking together in the park, sitting together on a bench, and the Russian Government Official #1 placing a shopping bag into a plastic bag held by Lazaro".
Shortly after his return to the US, Mr Lazaro - who had appeared to be "struggling financially" - paid off nearly $8,000 in tax bills, the documents state.
An 11th suspect, Christopher Metsos, said to be an SVR agent who repeatedly came to the US to meet the alleged spies and who is still at large, is accused of passing money to them.
One of the alleged incidents was a "brush-pass", in which Mr Metsos and a Russian government official "each carrying an all-but identical orange bag" swapped bags at a station in Queens, New York, while passing on a stairway.
The bag given to Mr Metsos contained cash, the court papers claim, some of which was buried in upstate New York. It was dug up two years later by two of the suspects from a spot marked by a "partially buried brown beer bottle" that the FBI had under surveillance.
In another "brush-pass" in 2009, a Russian government official is alleged to have dropped a shopping bag into a rucksack carried by suspect Richard Murphy as they passed each other on stairs at White Plains station in New York state.
Intercepted messages suggest that brush-passes were also used to hand over fake travel documents, the documents state.
A safe deposit box searched by US law enforcement agents in New York City turned out to contain birth certificates that did not match any municipal records.
Another searched in Boston, Massachusetts, contained photographic negatives of one of the suspects in her 20s. The name of the company that produced the film remained intact on one only negative - the firm, Tacma, was a Soviet one, US agents say.
The same box also held a copy of a Canadian birth certificate in the purported name of one of the suspects, Donald Heathfield. "While the Canadian Birth Certificate appears to be real, I have learned that the real 'Donald Howard Heathfield' is dead," the court document reads.
The papers also allege the suspects travelled on false passports.
A decoded message to Tracey Lee Ann Foley, accused of using a fake British passport provided by the SVR, reads: "Very important: 1. sign your passport on page 32. Train yourself to be able to reproduce your signature when it's necessary. 2. Pls, be aware that you just visited Russia... If asked, we suggest you use the following story: you flew to Moscow on Mar 16 from London for example flight SU 211 to participate in business talks..."
She is told to destroy the memo after reading.