The Avengers (1961)

S3E1 Brief for Murder

With the savvy guidance of the Lakin brothers, a man accused of treason is acquitted. However, Mrs. Gale suspects Steed's involvement and reaches out to the press. Steed confronts her, warning her to retract her claims or face dire repercussions. Before long, Steed finds himself on trial for the murder of Mrs. Gale.