Forrest's new case for children's-book writer Lyon Wentworth begins with a bang--Lyon is aboard a hijacked bus and, handed a gun by someone else, he kills the hijacker--but winds down into a series of complicated whimpers. Who was that mystery passenger who handed Lyon the gun and disappeared in the ensuing commotion? Who is the other mystery passenger who is the only one (aside from Lyon) not blown up when the same group takes a bus the next day? And who is making anonymous phone calls to Lyon, as well as trying to kill him when he indulges in his favorite hobby--ballooning? Unfortunately, it all tums out to involve the mob and some secret tapes (evidence of a mob front) that have been hidden in a Kentucky cave--as Lyon and wife Bea discover by tracking down the identities of those mystery men. But the only really intriguing mystery is how Bea, Connecticut's Secretary of State and a candidate for Congress, finds time for all this sleuthing. Other implausibilities also pop up, along with Forrest's tendency toward cuteness (especially off-putting amid such a lot of violent death), but this is fairly swift and basically good-natured stuff--a slight improvement over Forrest's last, Death Through the Looking Glass.