I. In which "The Life and Adventures of Nicholas Nickleby" is introduced and described, albeit as a series of numbers, and the producers form an unexpected alliance . . .

What the audience of "Nicholas Nickleby" sees as an ever-changing epic of the new characters and crises is stagecraft gone berserk backstage. For 8 1/2 hours at a stretch, with barely a few minutes to pause for a cup of coffee, about 100 people race through the cramped offstage rooms of the Plymouth Theatre. Four hunderd costumes! Nine hundred costume changes! Eleven dressers helping 42 actors make the costume changes! A staff of four adjusting 100 wigs and hairpieces! A scene of raucous precision that one actress describes as akin to military maneuvers.

About 1,000 props, ranging from chairs to the 105 muffins distributed and thrown in every show, are used, moved and reset for later use. There are six tons of iron in the scenery and as much original music as in the average musical comedy. The costumes amount to four or five loads of laundry, and two seamstresses spend most of the day repairing rips and tears incurred during the show.

There are 42 actors. The number of characters is not clear -- 119 are listed by name in the program, but the unnamed beggars, milliners and crowd members may bring the total to 250. The demands on the actors of playing an average of six characters each are so strenuous that a clothes dryer is kept ready during the show for perspiration-soaked costumes that must be used in later scenes.

Even the producing team is an odd marriage -- The Shubert Organization, headed by Bernard B. Jacobs and Gerald Schoenfeld, joined hands for the first time with arch rival James M. Nederlander to underwrite the estimated $4.4 million cost of bringing the production to New York. Nederlander had the rights, the Shuberts had the theater, and they enlisted the team of Nelle Nugent and Elizabeth McCann to handle production logistics. Result: five producers and a show that made the cover of Time magazine before it opened.

Of course the statistics for which many will remember the production are that the tickets cost $100 each and the show is an all-day enterprise, three days a week, or split between Thursday and Friday. The producers unblushingly call it "The Event of the Century," the biggest, longest, heaviest, most expensive ticket in the history of Broadway.

"It's going to raise standards and sights, show people what can be done if you go beyond the boundaries, said the Shubert Organization's Jacobs. "American actors will learn lots, American producers will learn lots and American directors will learn lots. They'll learn that if you give the public quality, they're willing to pay."

II. In which the question of Time and Money is discussed, which, being in its way astounding, provokes the concern of the public and the creators, in these Expensive and Difficult times . . .

As for the length, there are some precedents: the 16-hour productions of Robert Wilson; seven-hour movies like "War and Peace" or the original "Greed"; or the Broadway production of "Strange Interlude," which ran nine acts with a dinner break. But a $100 ticket?

The price is particularly ironic because the production was created by a company so accustomed to scrimping. The stage, for example, is framed by an impressionistic construction of ropes. "All the Broadway theaters have these marvelous hemp ropes in the flies," said designer John Napier. "We needed something simple and cheap so I said, 'Let's hang these down.' I love the anarchy in it."

The cost of putting on the show during its 14 weeks in the states will be $3.2 million, Jacobs estimates, and the cost of the set, transportation from England, rehearsal salaries, royalties, fees and union-related expenses was about $1.2 million. Thus, he figures, if the show grosses $300,000 a week -- of a possible $340,000 -- "we'll be lucky."

The ticket price did not please Britons. "I got a, uh, letter from (director) Trevor Nunn on the subject," said Jacobs, raising his eyebrows expressively. "He was very upset. I told him that we have to have super-superlatives here. We have two marketing tools -- The Event of the Century and the $100 ticket price. We would never have gotten all this publicity (without them.) . . . I consider the $100 ticket one of my proudest moments.

"Nobody understands the mathematics of this business as well as I do, and that's not the words of an egotistical idiot. And every way I figure it, it is possible -- if we eliminate all advertising the last two months, if we start selling out -- that we would make a profit of, at the most, $150,000 -- and that's at 99 to 1 odds. And on an investment of $4.4 million? Peanuts."

A further irony is that the play is basically about greed, the corrupting influence of money, and the injustice of poverty. "This is not a play that should only be seen by the elite," said one member of the company.

III. A short one, showing among other matters, that six months were spent in the rehearsing of the play; and how the event is temporal in nature . . .

The show itself is a consuming, enthralling creation. Devised by the company over a six-month rehearsal period which included improvisations and excerises such as writing short character descriptions for the designers, it includes every Dickensian type from the Crummles to Lord Verisopht to Mrs. Wititterly.

And when "Nicholas Nickleby" ends its run Jan. 3, that will be the end of it. It has been preserved for television, a four-part version expected to be shown in early 1983. The Royal Shakespeare Company will go on to the rest of its season, the props will be dispersed and the costumes stored. There is no possibility of the show's being held over by popular demand.

"By November they'll be fighting to get in the theater," said Jacobs, with a slightly worried, mostly confident smile.