Few authors have had as longstanding an influence on their genres as Agatha Christie.  In her more than half-century career writing detective fiction, she established (and then often went on to break) many of the expectations of the English “whodunit” puzzle story.  Her novels continue to be adapted for movies and television (recent examples being 2017’s Murder on the Orient Express and 2018’s Ordeal by Innocence), and their fingerprints are all over many crime novels to this day.  (For instance, Anthony Horowitz’s best-selling 2016 novel Magpie Murders, which I read while traveling last week, very explicitly both imitates and reacts to Christie’s style.)

Christie died in 1976, less than 50 years ago, so her works are still under copyright in most countries.  But her career was long enough that her early work has started to enter the public domain in the United States. That’s because the United States used fixed copyright terms, rather than terms based on the author’s lifetime, until the 1970s.  Christie’s first published novel, The Mysterious Affair at Styles, introduced what may be her most famous character, Hercule Poirot.  The novel entered the public domain in the United States in 1996.  In 1998, it was joined there by The Secret Adversary (1922), which introduced the detective couple Tommy and Tuppence.  (Copies of both novels are online.)

1998 was also the year that the US Congress passed the Sonny Bono Copyright Term Extension Act, which extended most copyrights for 20 years and froze the US public domain for published works– until the end of this year.  29 days from now, though, we should see more Christie works entering the public domain here, including The Murder on the Links, in which Hercule Poirot returns to solve a murder mystery in France.  The Murder on the Links was published in both the US and the UK in 1923, and its copyright was renewed in the US in 1950.  That copyright, like other 1923 copyrights still in force, is set to expire here at the end of this year.

Another English author’s famous detective also made his debut in 1923: Dorothy L. Sayers’ Lord Peter Wimsey.  Unlike The Murder on the Links, his debut novel, Whose Body? will not be entering the US public domain this coming January.  But that’s because it’s already in the public domain here (at least in its first edition), and has been since 1951, as I found out some years ago after a little detective work of my own.

How did this happen?  Under the copyright system used in the US in 1923, copyrights were initially secured for a 28-year term, and then had to be renewed in their 28th year to remain in effect.  A 1923 copyright, then, needed to be renewed in either 1950 or 1951 to get another term. (Initially that term was 28 more years, but was later extended to 47 more years, and further extended to 67 more years with the 1998 copyright term extension noted above).  Later changes in copyright law (which I’ll discuss further in later calendar entries) exempted many works first published outside the US from the renewal requirement.  However, when reading Barbara Reynolds’ biography Dorothy L. Sayers: Her Life and Soul, I found out that due to publisher delays, Whose Body? had come out first in the United States, before Sayers’ British publisher issued it.  So if its copyright wasn’t renewed, it was no longer in effect here.

A search through the US Copyright Office’s Catalog of Copyright Entries confirmed that no renewal had been filed for the book. So I digitized it and contributed it to my wife’s Celebration of Women Writers website, where you can read it today (if you’re in the US, or a country whose copyright terms last for 60 years or less from the author’s death).

In less than a month, American readers will have more mysteries to read online, share, or adapt– and not just from Christie (or Sayers).  Tomorrow’s advent calendar entry will feature another famous detective whose stories are all in the public domain almost everywhere in the world, but not quite all there in the US, and note one of the copyright battles that situation sparked.

2019 update: Link to The Murder on the Links, now in the US public domain, courtesy Project Gutenberg.