Dr. Sam Gaddis finds himself caught up in the mystery when he gets a tip about the possible sixth man, and then as he begins to investigate, discovers that those "in the know" are suddenly ending up dead. With the assistance of a very efficient MI6 officer and her foreign network, he manages not to get himself killed as he first tries to dig more deeply into the mystery, and then extricate himself when things get a little too hairy.
Quick, captivating, and highly enjoyable.