A Morris Dance at Russian Easter : THE BEGINNING OF SPRING <i> by Penelope Fitzgerald (Henry Holt: $18.95; 183 pp.) </i>

Spring is most violent where winter is most implacable. The foreground of Penelope Fitzgerald’s new novel, set in Russia in 1913, is the passage from a frozen March to the mud, snow-melt, prodigious budding and patchy blue of April. In the background is another changing weather: the erratic pulse of a revolution sprouting underneath the czarist ice.

Between these two weathers wander Fitzgerald’s comical innocents, an assortment of English expatriates living in St. Petersburg. Each has appropriated various bits of Russia and has got them, to various degrees, wrong. Their blithe myopia can’t quite make out the unpredictable shifts of the Russians around them, caught in their tempestuous double equinox.

Fitzgerald is one of the most gifted and elusive of living English writers. She writes with humor and an apparently gentle absurdity; there is something grave behind. Her books are archaic smiles, the corners turned down, devoid neither of compassion nor of distance.

Her theme is the English theme; which always and ever is that of a world in decline. Fitzgerald’s decline lies not in politics, economics or morals, but in a dwindling sense of reality. She will place her English in houseboats, as in “Offshore,” or abroad, as in this book and in “Innocents,” set in Italy. They never quite touch ground.

The Russians in “The Coming of Spring” move with a sense of incipient tragedy, though they can be very funny while doing it. The English interpret the ground tremors not as tragedy but as unreliability.

The grave comedy of “Spring” centers around Frank Reid, the most innocent of the expatriates. He is a good and just man, but he is always catching up with what is going on. He is neither weak nor foolish; it’s simply that the world at the turning of the seasons is moving faster and worse than he is.

Everything eludes him. He comes home one day from the printing factory he inherited from his father to find a messenger sipping tea in his kitchen. The messenger has been summoned to pick up a letter for him from his wife, Nellie. Frank is told why a messenger is needed to deliver a letter within the same house. He gets a reasonable answer, but it is the reasonableness of “Alice in Wonderland.”

Nellie writes that she has left with their three children. A theatrical approach being expected by the servants, Frank makes a dramatic announcement of the news. Theatrically, they weep and exclaim, although they have just helped her pack.

The following morning he gets a phone call from the station master, a friend. The three children have been sent back, along with a clothes basket. There is a note of reproach in the station-master’s voice, also in the demeanor of the horse-cab driver whom Frank asks to wait at the station. Also in the attitude of Dolly, the oldest of the children.

Annie, the youngest, had been impossibly restless on the train. It was hard on Nellie. “You shouldn’t have expected her to manage by herself,” Dolly scolds him. “She had to send her back; we weren’t a comfort to her.” It is another of Fitzgerald’s odd and oddly intoxicating displacements. It is also intensely touching; a child who shifts the blame to her father because she trusts him.

Why Nellie has left and where she has gone is a mystery until the end of the book. It is not a mystery anyone bothers much about; the real question is how Frank and the children will manage. The question serves to introduce an assortment of characters offering consolation or help.

There is Selwyn, Frank’s English assistant. He writes poetry, wears a Russian peasant blouse under his frock coat and is a disciple of Tolstoy. Tolstoy tells him he is boring but not to mind about it.

Selwyn will go through various transformations; the lack of clarity about just what he is up to moves along the book’s slender plot. He begins by telling Frank that his loss is a cause for rejoicing. “No it’s not,” Frank replies. “What a good man,” one of the servants says of Selwyn afterwards. “Always on his way from one place to another searching out want and despair.”

Mystic Russia, courtesy of Selwyn, is one of Frank’s crosses. Another is the hearty and marginally sincere embrace of Kuryatin, a friend and business associate. Kuryatin takes the children into his household but the arrangement lasts barely an afternoon. A pet bear is given vodka, smashes up the dining room and catches fire when a servant throws burning coals over him.

Water would have been of no use, Ben, Frank’s son, instructs his father as he is taken home. Bears like water, he explains; fire was necessary. Even his children are ahead of Frank.

Another offer comes from the wife of the English chaplain. She has a spare governess who has fled the chaos of a Russian country estate. The woman is too depressing, though; the children will never accept her.

“Miss Kinsman was dowdy,” Fitzgerald writes, “another of the words that couldn’t be translated into Russian, because there was no way of suggesting a dismal unfashionableness which was not intentional, not slovenly, not disreputable but simply Miss Kinsman’s way of looking like herself.”

Selwyn produces Lisa, a young woman from the country whom he claims to have met weeping at the handkerchief counter of the local department store. Frank hires her as governess and falls in love. But she is connected with the underground; before long, she has to flee the country. Here as always, Selwyn’s role is unfathomable.

A whole tangle of elusive schemes and subplots takes shape around Frank. The secret police appear, the printing press is in danger, and spring advances more and more disruptively.

Frank sees, but only dimly. He is not a dim man, though, in fact, he is a kind of patient hero. If his sight is fuzzy, it is a comic English fuzziness, but it is also something more. The world is shifting in its cloud of unreliability, and the dust gets in his eyes.

Fitzgerald has written a lovely book; a comedy lit by writing so precise and lilting that it can make you shiver, and an elegy that nods at what passes without lamentation or indifference.