Labour’s Loves Lost : A LANDING ON THE SUN <i> By Michael Frayn</i> , <i> (Viking: $21; 256 pp.)</i>

Jessel, the archetypal British civil servant, sits in his regulation office in Whitehall: a desk, a hat rack, two chairs, a view across the air shaft, and files in a neat pile. It is his purely abstract kingdom. He is the perfect instrument, a samurai of administrative procedure, existing to be the cog between other cogs. He describes his nirvana, his entire absence from himself:

“On the desk in front of me lie two human hands. They are alive but perfectly still. . . . These hands, and the crisp white shirtsleeves that lead away from them, are the only signs of me in the room. . . . Sometimes my own phone rings, and the voice that answers it is here inside the room, emerging from somewhere about the point where my two shirtsleeves meet. Because, of course, I have my voice in here with me, as well as my hands. I’d forgotten that.”

His office life divides into manageable units, each contained in a file folder. Of course, each evening he must leave the folders and go home to a much less manageable life. His wife is in a madhouse, his unhappy little son is looked after by an indifferent baby-sitter, his house is graceless and cold. Everything there, he reflects as he sits down to cold meat, his son having cried himself to sleep, “was chosen by me, worn by me, cooked by me, repaired by me. This is why I am not at home here.”

We know, right here at the start of Michael Frayn’s pointed and desolate comedy, that Jessel is to be plucked out of his desert domain. The plucking will not be done by a mysterious midnight summons, but by his two objectified hands pulling out a clean file and printing Summerchild on it.

A phone call from his superior has informed him that a television program is interested in the death, 15 years earlier, of a colleague whose body was found in one of the little alleys running through the Whitehall complex. Summerchild seemed to have fallen accidentally, Parliament was told at the time, and certainly it had nothing to do with the dead man’s humdrum job in an all-but-functionless bureaucratic appendage entitled the Government Commission. Jessel is instructed to prepare a brief report, in case television continues to pry.

And down the rabbit hole he tumbles. For a bit, Jessel--and we--think we have spotted George Smiley or James Bond disappearing around a bend in the tunnel, hand in hand with the departed Summerchild. Files have vanished; there is a reference to a mysterious Strategy Unit. Jessel, his gray beard neatly trimmed, may be meticulous and poor but he is a Civil Servant unleashed, and unstoppable. He ends up in a disused storeroom in Whitehall’s mansard roof.

Its grimy window offers a view of London, of St. James Park, and of a corner of the prime minister’s garden. The cereal and Brillo cartons stacked along the wall offer a view of the wild human heart as battlefield between passion and order, life contained and life uncontainable. They offer the romance of Summerchild and Serafin, a blue-eyed, gray-haired Oxford don who is a student of phenomenology, the mother of three children, and a free spirit with a Slavic soul.

“A Landing on the Sun” tells the wacky and exhilarating story of how Summerchild and Serafin got up into the garret, what they did there and what became of them. On that level, it is loony comedy with a mournful ending. Intermittently, it is a lovely satirical speculation on the ways of bureaucracies and academics, on the uses of order and disorder, and the deepest opposite twists in men and women.

It is 1975. Harold Wilson has won the election, the Labour Party has taken power, and the bureaucrats are nervously watching for threats and opportunities. Summerchild’s boss sees an opportunity in a Wilson phrase about a strategy to improve the quality of life. Some Labour intellectual has suggested that Serafin be tapped to think about it. She arrives in London looking for quarters. Summerchild, assigned to be her bureaucratic watchdog, inveigles her up into the Government Commission attic--just like Oxford digs, he notes--where she will do no harm.

But chemistry happens. It is intellectual chemistry, at first. Serafin asks her deputy what he understands by Quality of Life. Washing machines? he suggests. She is smitten; he is the perfect touchstone and ballast for a philosopher’s flights. She floats off on speculation, and he, startled, disapproving, and bit by bit delighted, follows. Clearly, what the prime minister needs is a metaphysics of desire.

This is a long way from washing machines, and a marvelously long way from anything the prime minister may or may not have had in mind. But soon, Serafin and Summerchild are exploring the concept of happiness; as a friend is happy, or possibly, a lover, she suggests. For his part, Summerchild draws up a bureaucratic minute examining his own life. He is comfortably married, and he has a good job and a nice family. Is he happy? That is a political question, he concludes; it is up to her to decide.

The transcripts of their discussions end abruptly. Their secretary has quit in shock. From there on, Jessel works with tapes. Talk gives way to sounds: ambiguous ones, as much domestic as connubial, at least at first. “Honey!” Summerchild breathes, but it seems to refer to their teatime. Soon, though, there are the sounds of an inflatable mattress being stuffed through the skylight and onto the roof. The lovers have landed on the sun; the affair is in full swing. Before long, it will end, though not until Summerchild is drawing up plans to smuggle in a refrigerator and build a loft on the roof for visits by Serafin’s children. It is moon-madness and soon it is moon-set; absurd, comical and disquieting.

It is something else, as well. Jessel, as he goes through the papers and listens to the tapes, gets caught up in the whirlwind. More and more, he identifies with Summerchild, his prim alter ego who, having heard Pan’s pipes, capers Dionysically on the government’s rooftop and, eventually, off it. Jessel begins to speak of the lanky, red-haired Summerchild as “I”; at one point, he describes his own gray hair as red. Lava chunks from his besotted investigatory volcano land in his South London life, with disrupting and inconclusive results.

Half-committed, he begins to court Summerchild’s daughter whom, coincidentally, he had known at school. We will not know until the end whether the igneous discharges from Whitehall’s garret will burn on, or burn out. Frayn’s ending is both sober and enlarging. “Landing on the Sun” is something more than a delight.