The most obvious place to observe Clark's skill is near the ending of Let Me Call You Sweetheart. The climax is nicely managed, with every character in precisely the right place at the right time to allow for a rip-roaringly suspenseful unveiling of villains and the saving of Kerry and Robin. Throughout the novel, Clark had been dropping clues, but she had also been subtly developing the theme of obsession. In Dr. Smith it was obvious, and he seemed truly insane; but Kerry is obsessive, too. Note how once she has her mind focused on a problem, she will not let it go until she has solved it. She even dreams about it. Robert Kinellen is obsessed with his social position. Jimmy Weeks is obsessed with staying out of prison. Skip Reardon is obsessed with his innocence. Beth is obsessed with Reardon, and so on. Some of the...