Holmes & Watson Investigate

Holmes & Watson Investigate is a 2017 British television series broadcast on the BBC and based loosely on the characters created by Arthur Conan Doyle. It is the second modern iteration formed by the BBC, after Sherlock. It, however, has no relation to Sherlock and only shares characters, who have largely different personalities. It premiered its first season in October 2017.

Cast
Joseph Fiennes as Sherlock Holmes

A former Criminology lecturer who forms a detective agency with his old university friend Marcus Hooper. But when Hooper is mysteriously murdered, he must find a new partner or lose his business. He has a quick wit and can be blunt, but is warm towards his clients and eager to help.

Ewan MacGregor as Dr. John Watson

A retired army doctor who, while attending the funeral of an old colleague Marcus Hooper, meets Sherlock Holmes and they strike up a friendship and then team up to solve Hooper's death. Watson eventually joins Holmes' detective agency and takes over from Hooper.

Winona Ryder as Irene Adler

Sherlock's long-term girlfriend and the mother of his son Sherrinford and a detective in her own right, she serves as a tech expert and researcher for Holmes and Watson, but is often off on her own side-adventures, be it saving an international diplomat's daughter from execution or protecting her neighbour from life imprisonment.

Diana Rigg as Mrs. Caroline Hudson

Sherlock's godmother and former guardian of Sherlock and Mycroft, she's a retired teacher and prior to that she worked with the Holmes boy's parents in MI5. She lives in 221A Baker Street, which she owns along with 221B, which serves as the offices of Holmes & Watson Investigations. She volunteers as the agency's secretary.

Jason Isaacs as Mycroft Holmes

Sherlock's brother who works at MI5 in a superior admin position, he has an all seeing eye over the country and is usually the source of the agency's high profile cases. He is often dismissive of his brother and his adoptive mother, but he cares deeply for them both.

Kate Winslet as DCI Giuliana Lestrade

Mycroft and Sherlock's childhood best friend and a high ranking police officer in New Scotland Yard, she frequently turns to her friends for help when it comes to cracking a hard hitting case. She has a close relationship with Irene too, serving as godmother to Sherrinford Holmes.

Hayley Atwell as Jane Moriarty

A former student of Sherlock's, he had her removed from the course after showing concern for her mental stability, crushing her dreams of one day being a great detective. She uses her skills of deduction to tease and manipulate Sherlock and those around him to her advantage, with the aim of eventually seeking revenge.