In one of the highest profile and most memorable criminal mysteries in recent years, the death of the MI6 spy Gareth Williams, found in a padlocked holdall in his London home, will be attempted to be solved by an inquiry featuring over 30 witnesses.
There are a multitude of unanswered questions for the investigation to try to answer, but here are some of the key mysteries still outstanding:
Gareth William's investigation so far, in pictures...
Williams was found dead in a Government flat in Pimlico in August 2010.
After excelling at university at mathematics, Williams worked as a cipher and codes expert at the Government listening station, GCHQ.
Williams was then seconded to work at the Secret Intelligence Service headquarters in Vauxhall, London.
CCTV captures Williams entering Holland Road Tube Station on the 14th August 2010.
Caught on CCTV at Holland Road Tube Station the same day.
Seen the next day on CCTV in Hans Crescent, London
His body was found in a holdall in this Pimlico flat on the 24th of August 2010.
Williams' funeral was attended by Sir John Sawers, head of SIS.
Screengrab from a video reconstruction showing a yoga specialist trying to lock himself in a sports holdall unaided
Screengrab from a video reconstruction showing a person trying to close the zip and padlock themselves in a sports holdall unaided