For years, I have been a big fan of the Ian Rutledge series written by Charles Todd. Set in post World War I era, the series is steeped in the atmosphere ofBritain during this time. More importantly, the series looks at a brilliant Scotland Yard detective who is still shell shocked from his time during the Great War.  Todd has kept the high standards in this series since it began with A Test of Wills in 1997. So I am quite interested to learn that Todd will be launching a new series with A Duty to the Dead, due out in August from HarperCollins A Duty to the Dead will continue Todd’s look at the horrors of Word War I, this time through the eyes of Bess Crawford, a battlefield nurse.Todd is one of the handful of authors who have used the WWI background as a way of looking at society, survivors’ guilt and Britain during the first part of the 20th century.Todd wrote one previous standalone, The Murder Stone, about a young heiress in 1916 who returns to the rural estate where her powerful and beloved grandfather is dying of a stroke.Todd, the writing name for mother and son Charles and Caroline Todd,  has made my annual list of the best mysteries for several years. Judging just from previous history, I think that readers will embrace Bess Crawford as they have Ian Rutledge.  While some authors will write only one series – and carry it on for decades – I’m always enthusiastic when an author tries something new, especially when they return to their regular series.Sometimes it seems as if the author returns that regular series a little fresher, having had a nice and sometimes much needed vacation from their regular characters.  I never want Michael Connelly to give up Harry Bosch, at least not for several years, but his breaks have only served to make his series even better. Connelly’s latest The Scarecrow comes out May 26Harlan Coben’s stand alone thrillers put him on best sellers lists, but he still returns to Myron Bolitar now and then. Laura Lippman’s stand alones have been some of her best work, but I always like to see what’s going on with Tess Monaghan.Other authors such as Donna Andrews, Laurie King, Charlaine Harris – dear me, the list goes on and on – have given us two or even more series.The winner in all of this has been the reader.Do you have a favorite second series from an author?PHOTO: Caroline and Charles Todd; photo courtesy HarperCollins