It's the stuff of Sherlock Holmes...
A spy found dead in a bag he couldn't have locked himself into, in a flat with no evidence that anybody else had been inside.
Establishing what happened to Gareth Williams is now the task of Westminster Coroner Dr Fiona Wilcox who will next month hold an inquest.
Today's review of evidence to be examined revealed several new and surprising facts; from a DNA blunder which has sidetracked the investigation for eighteen months to the dramatic claim by Mr Williams' family that other spies were involved in his death and possibly a cover up.
Of course none of this makes it any more likely we will get to the bottom of what happened in August 2010 at the MI6-owned apartments in central London.
Evidence outlined today makes plain what lies at the heart of the problem.
Mr Williams was found inside a waterproof red bag which he could not locked from the inside.
Two experts will attest to this next month and Dr Wilcox is so keen to establish this as fact she even suggested a demonstration before the court.
That means someone else must have been there when Mr Williams got into, or "was placed" as his family's lawyers said, the bag.
Yet police have found no fingerprints or DNA inside the flat belonging to anyone else and the are no signs the door to his rooms bad been tampered with.
This has given the Williams family the impression that, in their words:
– The family of Gareth Williams
The unknown third party was a member of a some agency specialising in the dark arts of the secret services or the evidence was removed post mortem.
I understand there is not yet a specific allegation that Mr Williams was killed by another spy, just that they were present when he died, though that remains to his family a possibility.
Other revelations included a DNA blunder which the coroner warned could have implications beyond this case.
Private firm LGC Forensics told police early in their inquiry they had found a mixed profile on Mr Williams' hand.
But earlier his month it emerged the profile was actually that of a scientist who went to the scene.
This should have been picked up at the lab but apparently two numbers in digital code for that profile were entered the wrong way round generating a false "suspect" profile.
LGC today apologised to Mr Williams' family who had hoped the DNA would lead them to whoever was with their son when he died.
It turns out there have been other red herrings along the way.
More than a year ago police appealed for a couple who had buzzed on Williams' door from the street asking for a man called "Pier Paolo" to come forward.
They now have and it seems Mr Paolo lived next door all along and his friends had simply gone to the wrong house.
Around thirty people will be called to give evidence including Mr Williams' sister and three of his colleagues from GCHQ, who will give evidence anonymously to protect themselves and national security.
Quite what light they are able to shed on the mysterious death of this brilliant yet private man remains to be seen.