SunnyMarch, Chapter One Pictures, and Anonymous Content are producing the limited series. Cumberbatch will also serve as an executive producer along with Adam Ackland under their production company SunnyMarch banner. Sophie Gardiner, Mark L. Smith, and Edward Berger are also executive producers under Chapter One Pictures. Keith Redmon for Anonymous Content and Cliff Roberts for Syndicate Entertainment are executive producers as well.
Similar Topic: Felicity Jones & Shailene Woodley are involved in Netflix's adaptation of "The Last Letter From Your Lover."
Here is the goodreads synopsis of The 39 Steps:
Adventurer Richard Hannay, just returned from South Africa, is thoroughly bored with London life-until he is accosted by a mysterious American, who warns him of an assassination plot that could completely destabalise the fragile political balance of Europe. Initially sceptical, Hannay nonetheless harbours the man-but one dayreturns home to find him murdered... An obvious suspect, Hannay flees to his native Scotland, pursued by both the police and a cunning, ruthless enemy. His life and the security of Britan are in grave peril, and everything rests on the solution to a baffling enigma: what are the 'thirty nine steps?'
First published 1915
Source material: Deadline.com