The Russian government has shrugged off Britain's decision to name two Russian citizens, believed to be working for Moscow's military intelligence agency, as the alleged culprits of an attempted murder of a former double agent on British soil with a highly toxic nerve agent.
"The names, just like the photos published in the media, say nothing to us," said Foreign Ministry spokesman Maria Zakharova, who urged the British to "move away from public accusations" by providing further concrete evidence.
Moscow's denials were fully expected; no country owns up to its intelligence services' activities.
Still, the release of Britain's forensic evidence will have much wider ramifications for Russia's relations with Western countries.
Mr Sergei Skripal, a Russian intelligence agent who betrayed his country and covertly worked for the British, was found slumped unconscious together with his daughter on a park bench in the southern English city of Salisbury on March 4.
Because another Russian double agent was murdered in London with the use of unusual radioactive fluids more than a decade ago, the British authorities assumed from the start that the Skripals' poisoning was due to foul play and called in experts in toxic substances.
That decision not only saved the lives of Mr Skripal and his daughter, but also provided a quick identification of the compound which poisoned them: a military-grade Novichok nerve agent, a class of highly toxic chemicals developed by the Soviet Union during the 1970s and 1980s.
Moscow denied any responsibility for either the attempted murder or for producing the chemical substance, but independent labs subsequently confirmed the British findings, and many Western governments were so convinced by the evidence that they joined Britain in protest by expelling Russian diplomats. Still, trying to piece together how the Skripals were poisoned and who did it looked like a search for a needle in a haystack, until a further tragic accident provided vital clues.
On June 30, Ms Dawn Sturgess and Mr Charles Rowley, who rummaged through public charity boxes, picked up what looked like a perfume bottle. Ms Sturgess sprayed herself with what she believed to be perfume; she died a week later from Novichok poisoning, but she inadvertently discovered the murder weapon used against the Skripals.
Once this was clear, searching through footage from closed circuit TV for people who were both near the Skripals' home and near the place where the fake perfume bottle was discarded was easier.
And, once the suspects were identified, their identities could be corroborated with immigration records of people entering the United Kingdom. According to British prosecutors, the suspects used genuine Russian passports with fake names. And their movements conformed exactly to the timetable of the attempted murder. The suspects also apparently left some faint traces of the Novichok substance in their hotel bedroom. It was a case of good policing and smart use of technology, such as facial-recognition software and database mining.
The chances of the accused ever standing trial are virtually nil; the Russian Constitution does not allow the extradition of its citizens, and Moscow is highly unlikely to pursue the matter. Still, the revelations put Russia under some pressure.
First, it is clear that although this intelligence operation was clever, it was not clever enough. The basic fact remains that the plan was to murder someone and leave no traces, but the result is that the target remains alive, and alleged perpetrators were apparently identified.
Someone in Moscow also made an elementary mistake of issuing the two agents with passports bearing almost consecutive serial numbers, something which cannot happen by accident; obviously, Russian intelligence agencies get batches of blank passports to use, and these are numbered sequentially.
The result of this error is not only that the two Russian agents were quickly identified, but also that Western intelligence agencies around the world will now be searching their databases for other Russian passport-holders with numbers from the same batch.
Either way, the agents named will never be able to leave Russia again without fearing arrest abroad, since Moscow does not know how much further information Britain may have about their real identities, or their previous contacts with other Russian agents in the West.
But the biggest impact of the British revelations is political. The agents accused of the murder appear to belong to the GRU, Russia's military intelligence serviceaccused by the Americans for being behind the alleged interference in the 2016 US presidential election.
So, what began as a bizarre assassination attempt in a sleepy English city will spark a bigger confrontation between some of the world's top intelligence agencies for months, if not years to come.
