The estate of Sir Arthur Conan Doyle has asked the Supreme Court to review a recent appeals court decision affirming that that the character of Sherlock Holmes is in the public domain.

Specifically, the estate is seeking a delay of the Seventh Circuit’s June ruling, while it prepares its full appeal. The request comes after the Seventh Circuit refused to stay its decision on July 9.

The filing is the latest (and likely the last) twist in the legal battle over Sherlock Holmes' copyright status, and comes after the Seventh Circuit in Illinois affirmed a December 23 declarative judgment, in which judge Ruben Castillo declared that the public "may use the pre-1923 story elements” of Sherlock Holmes (as well as other characters and elements of Sir Arthur Conan Doyle’s iconic mystery series published before 1923), without seeking a license. The basic cut-off date for the public domain in the U.S. is generally considered to be 1923.

Writing for a three-judge panel of the Seventh Circuit, Judge Richard Posner wrote that the court could not find "any basis in statute or case law for extending a copyright beyond its expiration,” and held that “when a story falls into the public domain, story elements, including characters covered by the expired copyright become fair game for follow-on authors.”

The federal suit was brought in early 2013 by author and scholar Leslie Klinger. Klinger, who told PW that the suit became necessary after the Doyle estate attempted to extract a license fee for a book he was co-editing, In the Company of Sherlock Holmes (Pegasus Books) with author Laurie R. King, the bestselling author of the "Mary Russell" series of mysteries that also feature Sherlock Holmes.

The decision excludes roughly 10 of Conan Doyle’s Holmes stories, which remain under U.S. copyright protection, and which Klinger had excluded from his suit. But roughly 50 other stories featuring the famous characters are now officially in the American public domain.

The Holmes estate, however, contends that because Doyle was still developing the character of Holmes well past 1923, the character merits protection.