Murder on Clam Pond, the first Cape Cod mystery featuring narrator-hero ""Mac"" McFarland (a middle-aging reporter), was a fairly engaging variation on the cozy-village formula. This time, newsman Kiker tries something quite different: a blend of political melodrama and action-sleuthing (Ã¡ la Dick Francis) that's entertaining if far-from-mysterious. Now living in unwedded semi-bliss with classy, youngish girlfriend Kate, Mac sees a yellow car submerged nearby in ""the Cut""--a Chappaquiddick-like inlet--and finds, strapped into the passenger seat, the drowned body of a young Susan Jacobs. Was it accident--or murder? (An autopsy reveals alcohol and drug use.) Furthermore: is the drowning connected to the fact that Sen. Dolph Bridges, a presidential hopeful, has set up informal campaign headquarters on a nearby Cape estate? Susan, you see, a recent Cape arrival, used to work in Washington--on the staff of a subcommittee chaired by. . .yes, Dolph Bridges. Mac, working on a magazine-profile of Bridges (whom he's always liked), does some detecting along the way, in D.C. and N.Y., eventually uncovering--no surprise--a Bridges/Susan affair. The Senator's staff tries to buy Mac's silence; other, more shadowy henchmen take a violent approach--including a near-fatal attack on Kate. And some not-so-obvious motivations surface before the downbeat fade-out. Despite the blatant Chappaquiddick aroma: tasteful, crisp suspense--with convincing portraits (political cronies, wives, groupies), agreeable dollops of sentiment, and sturdy treatment of some ethical issues faced by journalists.