(written Dec 6, 2015 catching up, actually had not recorded when I actually read this, so the date could be off, but it was definitely part of my Gilbert/Ambler binge early 2015)
I enjoyed this one as all Gilberts, but it is not my favourite. Focuses on the older people, who are cool, but I didn't find them particularly compelling. The culprit didn't seem super connected with the rest of the story either, so the ending was not totally satisfying. Still, I'm picking nits because all of Gilberts books are worth reading.