The 6th Temperance Brennan book
2003 Arrow (2004)
Recommendation: Previous books
Set in Carolina in summer, a number of small, almost routine, analyses of bones prevent Tempe from escaping for a vacation; but when threatening letters start arriving, she and Andrew Ryan (who just happens to be visiting) begin to wonder if they are linked. The different strands provide plenty of interest, along with suspense, and the low key potential for romance (maybe). A really good story.