Department Q is a series of crime thriller novels by Danish novelist Jussi Adler-Olsen. The series follows Carl Morck, one of the best homicide detectives in Copenhagen who has been promoted to the cold case department.

The Department Q series originally began in Danish with Kvinden i buret in 2007. In 2011, it would be translated into English and published in the UK as Mercy and in the USA as The Keeper of Lost Causes. Below is a list of Jussi Adler-Olsen’s Department Q books in order of when they were originally published in their English language editions:

Publication Order of Department Q Books


The Keeper of Lost Causes(2011) Best Hardcover PriceBest Paperback PriceBest Kindle Price
The Absent One(2012) Best Hardcover PriceBest Paperback PriceBest Kindle Price
A Conspiracy of Faith(2013) Best Hardcover PriceBest Paperback PriceBest Kindle Price
The Purity of Vengeance(2013) Best Hardcover PriceBest Paperback PriceBest Kindle Price
The Marco Effect(2014) Best Hardcover PriceBest Paperback PriceBest Kindle Price

Notes: The Keeper of Lost Causes was published as Mercy in the United Kingdom. The Absent One was published under the title of Disgrace in the UK. A Conspiracy of Faith is titled Redemption in the UK. The Purity of Vengeance is titled Guilt in the UK.

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  • cassandra

    this list is misleading. there are three books so far, and all have different titles for the US. the US series is: The Keeper of Lost Causes, The Absent One, A Conspiracy of Faith (and soon The Purity of Vengeance). In Europe those same books are called: Mercy, Disgrace and Redemption.

    • Brandon

      Thanks! I didn’t see this post till now, but you’re right. I had a bad source.

  • Peter Ryan

    Is The Purity of Vengeance a different book from Redemption? On JAO’s website, these have different names again! Arghhhh. Great books though!

    • Brandon

      I’m a little confused myself. I will do my best to get this straightened out ASAP.

      However, I can tell you that The Purity of Vengeance won’t be out until December 31st.

  • J

    Ok thank you all. I’m reading the first “The Keeper of the Lost Causes” here in the United States and my grandma wanted a christmas list so I was hoping find the next title

  • birdyabroad

    The notes section with the UK titles is still quite confusing – and the UK title for the 4th book should be “Guilt” and not “Contempt” (at least with Penguin…)

    • Brandon

      I’ll fix it so that UK visitors only see the UK titles. Thanks for your feedback – we’re always looking to improve the site.

      • Brandon

        Oops, it was already like that… Well, I guess I’ll just re-word it then. :)

  • Biterflame

    On Goodreads, it says that there are more than four books in this series (?!) I was wondering if anyone had any information on this.

    • Brandon

      It’s including The Marco Effect (“Marco Effekten” in Danish), which comes out in English later this year – September 9th, to be exact.