We will be kicking off the first weekend with a double bill for Parts 1 and 2.
The subsequent parts will each follow one weekend after another as detailed below.
PART 1 - Saturday 22nd February
PART 2 - Sunday 23rd February
PART 3 - Saturday 1st March
PART 4 - Sunday 9th March.
"A Study In Secrets" will be the fourth and final episode of the fourth series.
To see photos of the episode click here.