It began with a school trip to the Aran Islands for the transition year of Colaiste Raithin, an all-Irish secondary school in Bray, Co Wicklow. The pupils hadn't even got as far as their hostel on the first day when the school head, Gearoid O Ciarain and his deputy, Noirin Ni Chonghaile, were confronted by a man complaining that his house had been hit with what he thought was a stone.

Two possible culprits presented themselves. The first was a catapult bought by a boy in Galway. The second was what Andrew*, a 15-year-old, described as a "toy gun", bought while away on holiday. Both boys voluntarily handed up the weapons and denied hitting the house with anything.

The next day, they all cycled to Dun Aenghusa. Afterwards, the group became fragmented. Some returned to the hostel for their swimming gear, others apparently had gone back to rest.

Later at dinner, the two teachers noticed that a pupil seemed "very disorientated" and he admitted smoking hash that afternoon with three others. The three included Andrew. Mr O Ciarain recovered about £30 worth of the drug from another of the four, stored it with the catapult and the gun, and contacted the parents. Trapped on an island in gale-force winds, there wasn't much more that anyone could do.

On the following Monday, October 23rd, the principal brought both the hash and the gun down to Bray Garda station, where he says he was told that Andrew's toy was an air-action pellet gun, which required a licence. It was agreed that someone from the drug squad would be in touch.

Later that day, Andrew and his parents came to the school to meet the head and his deputy. After interviews with him and other boys, the head collated a number of allegations against Andrew, the gist of which was that another boy had "collected" the money for the drugs from three others and had passed it on to Andrew, who had done the £70 deal in Bray before travelling; that all four had smoked it on the train to Galway between the carriages, that they had smoked on the island and in the weeks beforehand; and that Andrew had taken an "illegally held gun" with him to Aran.

Pending a board of management meeting on November 6th, the principal suspended the four along with another boy who, it was claimed, had contributed to the fund but had not gone on the trip.

By now, the principal had concluded that two of the boys - Andrew, who had done the deal, and the boy who had allegedly collected the money for it and who was also alleged to have his own "independent supply" - were more culpable than the others. He drew a distinction between those "who obtained drugs from dealers and those who got them from other students". He decided to recommend to the board of management that the two boys be expelled and the other three suspended.

Though all five families were invited to the board of management meeting, three opted not to go; they had been given to understand that suspension and guarantees of future conduct would be an end to it. The other two attended with their sons. Andrew told the board that he knew he had made a mistake and apologised to it, to the head and deputy head, and to his fellow students whom he had let down. He asked for a second chance, as expulsion could ruin his future.

After contesting some of the principal's submissions, his father referred to his son's academic record - he is said to be an exceptionally bright boy who, with the other four, had done well in the Junior Certificate. He also referred to his contribution to the school in the area of music. He asked for a second chance.

Under questioning, Andrew admitted - for the first time, according to the head - to involvement in previous incidents. While both families agreed that their sons had been smoking hash, they questioned the manner in which blame had been apportioned. They preferred to talk of "sharing" drugs, not "supplying"; the money had been "pooled", not "collected". It was a collective decision to acquire, finance and consume drugs, they contended.

They were not taking the boys' behaviour lightly. Andrew's family had sought professional advice on what should be done to help him. The other boy had promised faithfully that there would be no recurrence, said his father; they had contacted the Garda, he said, and could get an officer to speak to their son.

Once the families had left, the head drew the board's attention to its solicitor's advice, one element of which became key to his subsequent stance. From this advice, he inferred that Andrew could be a legal "hazard" to other pupils and as such, could leave the school open to litigation if the "hazard" was not removed.

Opinions expressed by board members suggested little leeway for any of the five boys. There was "too much tolerance of drugs in society . . . This was the school's opportunity to come down hard on the issue"; "A harsh decision may be necessary here," said another, for the overall good of the school, bearing in mind the perception leniency could create among other parents; the school must be protected even if that required unpalatable decisions; failure to expel could limit the school's ability to deal with future cases of drug use if they arose; the Juvenile Liaison Scheme was not a very effective scheme, suggested another, and referral to it might not be regarded as a severe sanction by the pupils.

Woven through the discussion was a concern about possible legal repercussions if "totally equal treatment" was not allotted to all five pupils or if "hazards" were not removed from the school.

The upshot was that by a verdict of four to one, all five pupils were recommended for permanent expulsion - including a boy who was alleged to have contributed money but hadn't travelled to Aran.

Mr O Ciarain says that he was "flabbergasted" by the decision; he knew that according to the boards of management constitution - which are subcommittees of the VEC - only the principal has the authority to recommend dismissal of pupils. But he was no more flabbergasted than the parents of the three boys who hadn't attended the meeting.

"We all wanted the children to be dealt a bit of a lesson," said one, "but we honestly felt that expulsions wouldn't happen. The VEC doesn't expel children." While they summoned their legal advisers, the principal checked the rules and immediately reinstated the three boys for whom he had recommended suspension. The board made no objection.

But nine days later, at a second meeting called because it was felt to be "safer" to do so, the board did a complete U-turn. Each of the five families addressed the board. The parents of the boy accused of collecting the money stated that they would be withdrawing him from the school. That left Andrew and the three others. It was agreed that the three would be allowed back to school immediately, with the proviso that the parents of each would sign an undertaking that should he again be involved in any drug-related incidents in or around the school or during any school-related activities, they would voluntarily withdraw him from the school.

It was also decided, by a vote of five to one, to reinstate Andrew provided his parents signed the same undertaking. This they agreed to do. But the principal resisted, saying that he could not accept the pupil back in the school until such time as he received clarification from the VEC as to his own legal position, since he regarded the boy as a hazard to other pupils and he, as principal, had an obligation to remove all such hazards from the school. He wanted him suspended until the next Wicklow VEC meeting six days later.

In the event, the VEC - made up of mothers, a businessman and a parish priest among others - voted unanimously to uphold the recommendations of the second meeting. The head still stood firm.

Thus did a small local dispute balloon into a High Court matter, as Andrew turned up for school - backed by the board of management and the VEC - only to be turned away by the principal, who wanted "clarification of the points raised" in writing before he would accede to the VEC's decision.

While sources close to the board insist that he was given this clarification and had been assured that if anything happened he could not be held liable or negligible, this was not enough for the principal. "I was told I had no further responsibility," says O Ciarain, "but number one, I felt I had a strong moral responsibility and, number two, I was not happy that this was legally sound. If the advice two weeks earlier was that these boys should be removed, what was different now?"

What was different, it seems, is that the members had had a chance to reconsider. There was a feeling, said one of them, that Andrew had not been given a second chance and that expulsion was too severe: "There was no new evidence, but there may have been different slants . . . a greater understanding."

On the matter of the gun, for example, it was perceived to be a totally separate issue that had been dealt with correctly back in Aran.

Hugh O'Brien, the CEO of Co Wicklow VEC, will only say that "the members would have known that the decisions of the first board meeting had been quashed so they would have been considering everything afresh. It gave them a chance for second thoughts and they decided they would suspend rather than expel any person."

But it is part of the convoluted nature of this case that even that will be contested by Mr O Ciarain. He contends that the first meeting had not been quashed and that the two expulsions stood. He will contend that the second meeting was merely to hear the cases of the other three and that Andrew and the other boy were brought in only because of the possibility that new evidence might emerge that would reduce their culpability.

In any event, within weeks, Andrew's parents had applied for an injunction against the principal, to restrain him from keeping Andrew from the school and a permit for a judicial review of the principal's actions. In January they obtained both in the High Court and Andrew was back in school. Though a date was fixed for a full hearing last week, the case was postponed due to a shortage of judges able to run a case through Irish, and will probably be further deferred to the autumn, to the palpable disappointment of all concerned.

Andrew, says one impartial observer, is now a mere "sideshow" in what has become a war between Co Wicklow VEC and Mr O Ciarain. What makes this especially piquant is that the courts have ordered that the VEC - not previously cited by Andrew's parents - should be joined to Mr O Ciarain as co-respondents. But the rights or wrongs of teaching a 15-year-old a sharp lesson are barely an issue; everyone agrees that the case will be decided on issues of procedure raised by Mr O Ciarain.

Were any of the recommendations of the first board meeting valid? Was it valid to proceed in the second meeting using minutes that were still in draft form? Were Andrew's parents entitled to come by judicial review? And - an interesting question for lawyers and taxpayers - who is going to pay the legal bills, which according to one informed guess, may already have reached £100,000?

The war also continues to escalate at a separate level. Mr O Ciarain has been refusing to attend his own school's board of management meetings since April and he has written to the Department of Education charging the VEC with bringing the school into disrepute.

Meanwhile, the VEC is attempting to bring disciplinary hearings against Mr O Ciarain for his alleged refusal to supply names and addresses of pupils' parents whom it wished to contact to explain its position in the case. Though the VEC is his employer, Mr O Ciarain claims he is precluded from providing the lists under the Data Protection Act. The VEC's view is that this amounts to a failure to accept authority.

The Association of Secondary Teachers, Ireland refuses to comment on the case. Is the union supporting Mr O Ciarain? "He is an ASTI member and is therefore entitled to the support of the ASTI," was the careful answer from a spokesman.

The spiral is particularly distressing for Mr O Ciarain, an articulate, humorous man, who is said by all sides to be a "brilliant" teacher. The 48-year-old holder of a first-class MEd has been principal of the non-denominational Colaiste Raithin since its establishment 10 years ago.

After only four years of turning out Leaving Certificate classes and with under 300 pupils of all beliefs and backgrounds, it has produced two Trinity scholars and an annual clutch of valuable scholarships. Last year, one of its pupils got the second highest Leaving Cert result in Ireland. And it has managed to do this while balancing an unusually open, informal atmosphere between students, staff and parents with few discipline problems.

But, adds one supportive parent, nothing is black and white. Andrew too, is "a genuinely nice young fellow", outgoing, bright, comfortable with people of all ages and a serious musical talent. While his parents decline politely to give interviews, people who know them say they never thought the case would drag on to this point. They didn't seek another school for their son because he had not been expelled; they had the board of management and the VEC onside after all. It seemed just a matter of time until it was resolved.

Amid the jargon and legalese, it is easy to forget that at the heart of it all is a nightmare not only for all concerned but for any parents of teenagers, their teachers and the wider society.

"Hash is a peculiar issue, a big taboo - in education, in society. Parents go crazy about it, they freak out at the thought of it," says the principal of one Dublin school, who reckons that up to 80 per cent of youngsters in south Dublin have had a puff or two by the time they turn 17. "I'd say for everyone from the age of 11 to 12, it is totally accessible, openly available. It's so common now, yet it's incredibly hidden. And I've seen some awful things done to children over it."

This principal's strategy is to "try not to catch the children - because if you do you're stuck. But if I caught somebody outright I'd give them a chance."

It's not an uncommon view. Another principal admits that he has no "proper policy" on drugs in the school for similar reasons. Although he has had gardai in to talk about drugs, he has never wanted to raise it at board of management meetings "because some members would be so anti-drugs that they would give no leeway at all to the child . . . These are not drug addicts we're talking about. The vast, vast majority are experimenting and move on."

These principals are well aware that acquiring hash brings the buyer into "drug war" territory; that it is illegal and that if the user moves on to other drugs, it can get "dirty and nasty very quickly". Yet they make the point that in general terms they would tend to associate "loutish behaviour" more with alcohol: "The culture surrounding drink is worse . . . Among hash users, the danger is more to themselves, they're more likely to go into themselves and get more involved in drugs and maybe get into stealing.

"But I'm certain that the bigger problem by far is still the drink. I've seen so many tragedies, deaths and accidents as a result of it . . . "

Privately, individual gardai agree. One gives a vivid description of being on the city beat on a Saturday night.

"Those are a nightmare. Going on duty at 10 o'clock with eight hours ahead of you of domestic violence, drink-driving, rows and fights outside pubs and discos, arguments with taxi-drivers, fights on buses - and all of it down to alcohol. That, to me, would be the most serious problem we have. Cannabis users are more . . . well, relaxed. Of course driving while on hash is as dangerous as drink-driving and there are health aspects to it, but I think there should be some consideration given to legalising the sale of it. In a country with a massive alcohol problem like ours, I'm not sure that we have it in perspective."

Another senior garda who works in the field takes a more legalistic view - "it's illegal and that's that" - and believes that the figure of 80 per cent is "totally incorrect".

But even he believes that "it's not a frightening thing to discover a schoolchild smoking a bit of hash. It's not as big a deal as it used to be. Maybe I feel that way because I know more about it - and maybe I've seen worse things."

All this is happening in the context of a lively debate in Britain, where senior Conservatives are calling for the legalisation of cannabis and where many no longer view it as a gateway drug. A Police Foundation inquiry into drug laws, chaired by Dame Ruth Runciman, concluded last year that cannabis caused some harm but was less dangerous than alcohol or tobacco.

No one is arguing that it should be available to children, only that it should be placed in perspective. The Co Wicklow VEC shows little sign of going the Tory way, but it does appear to be grappling with the bigger picture.

"The VEC would always adopt a hard line on drugs," says the CEO, Hugh O'Neill. "We are not soft on drugs and we would be conscious of any hazards. But any case must be looked at on its own merits, in the light of the rights of individual students, and the right to an education as well. And, unfortunately, schools will increasingly have to take on the responsibility for tackling this kind of problem. But the answer is not to dump them out on society and leave them there."

But what is the answer for people like Mr O Ciarain in the meantime? Should the police always be informed? Can a 15-yearold child constitute a hazard? Is expulsion ever justifiable for such a young child? Is the day looming when no teacher will take the responsibility of escorting a school trip?

Or - as Mr O Ciarain believes - is it simply that "we have come into a tolerant society which in one sense, doesn't know where to draw the line"?

* Andrew is not the boy's real name