The 45-year-old actor will make his debut with the premiere of the second season on CBS, which will be shot in London.
In the episode, Sherlock Holmes is in London to revisit an old case wherein he is forced to meet his elder brother Mycroft Holmes, played by Ifans, reported Deadline.
Although not comfortable facing each other because of their past together, Mycroft allows Sherlock and Joan, played by Lucy Liu, to stay at his 221-B Baker Street home in London.