DIRK GENTLY’S HOLISTIC DETECTIVE AGENCY by Douglas Adams (Simon & Schuster: $14.95; 247 pp.).

In this whirligig of a novel, Adams has left behind the adventures of Arthur Dent from “Hitchhiker’s Guide to the Galaxy” and taken up with Svlad Cjelli, otherwise known as Dirk Gently, a London holistic detective who believes in “the fundamental interconnectedness of all things . . . missing cats and messy divorces a specialty.”

An old Cambridge acquaintance, Richard MacDuff, comes to him because he’s implicated in a murder. The threads of this murder, needless to say, in true Adams fashion are entwined with life, the universe and everything (to quote a previous title of Adams). And it’s not really clear why. The book is populated with delightful eccentrics, strange juxtapositions and a funny business about a horse. There’s a time-traveling ghost searching for surcease from guilt, a Prof. Chronotis who’s been at St. Cedd’s College, Cambridge, for simply ages and even Samuel Taylor Coleridge! All these fascinating characters--and especially Dirk Gently--are delightful, but somehow they don’t jell completely. The knot remains tangled at the end: All the dots connected do not make a coherent picture.