Strange Shores is (presumably) the last Erlendur book that takes place in the present.
I would totally NOT recommend
Strange Shores to anyone who hasn't read the rest of the Erlendur series. It just wouldn't be as meaningful if you hadn't already followed the character through all the earlier books. All through the series there are references to his early family life on a farm in the eastern fjords of Iceland, and to the loss of his little brother in a snowstorm when they were children.
Strange Shores is the culmination of all that long hinted-at history, and how it shaped the character of Erlendur and his penchant for digging deeply into long-buried secrets. Everything that came before leads up to this (seemingly) final story.
I hope you will enjoy
Silence of the Grave and
Voices, and that maybe you'll want to keep on through the rest of series. If not, that's fine too, of course!
I've just been particularly smitten with this author and this series, and have found these books to be some of the most rewarding mystery fiction I've ever read.