Consider this storyline and see if you can figure out the ending: there once was a man called Tony Ryan who wanted more than anything to entice his son, a pilot working overseas, to return home to Ireland, and so he set up a tiny airline. The airline was steadily working its way to rack and ruin, until a young accountant stepped in to save the day.

Not a traditional hero figure - in fact he was aggressive, rude and quite fond of swearing (think Gordon Ramsay rather than Jamie Oliver) but he turned out to be very, very good at giving airlines the kiss of life.

Tony Ryan ended up happily ever after as a multimillionaire, and the tiny airline grew to become the best managed and cheapest in the skies. Even the State airline was forced to drop its ridiculous prices, and Irish people were free at last to enjoy several European mini-breaks a year.

The airline's name? Yes, you've guessed it - Ryanair. And the leading man? Michael O'Leary.

Loved and loathed in equal measure, our mischievous hero likes nothing better than to keep everyone on their toes, pulling publicity stunts, breaking taboos and making a few enemies over the years.

And, like all good storylines, the Ryanair tale held a completely unexpected twist in store. Aer Lingus, formerly owned by the Government, was recently privatised in order to raise funds, and was listed on the Irish Stock Exchange.

The privatisation was going smoothly until, out of nowhere, O'Leary revealed Ryanair's plans to buy the airline. The sound of backslapping quickly turned to the sight of jaws dropping across the land.

O'Leary had thrown everyone off the scent during the summer by insisting that he had no interest in a "small regional airline" like Aer Lingus.

The board of Aer Lingus has turned down Ryanair's offer in no uncertain terms. This situation is known as a "hostile" bid, which seems like an understatement in this case.

Aer Lingus pilots are gambling their pension fund and other assets to buy up company shares in a frantic attempt to block the takeover, the trade unions are furious and the Government is scratching its head wondering why the advisers that it paid €30 million to failed to highlight that this might happen.

Having been taken by surprise by this turn of events, journalists, economists, stockbrokers, the Government, pilots and shareholders alike are now trying to predict the ultimate outcome.

The Government hopes that the takeover will be blocked by the European Commission on the grounds that it would create a near-monopoly on flights out of Ireland (between them, Ryanair and Aer Lingus control almost 70 per cent of traffic passing through Dublin airport), competition would suffer and fares would shoot up to levels not seen since the bad old pre-Ryanair days.

Some commentators say that the takeover would actually make the Irish aviation industry more competitive in the long run. Others are hoping for a "white knight" to come galloping over the horizon - another bidder who will save Aer Lingus from Ryanair's clutches.

And of course, O'Leary could have a few more tricks up his sleeve yet. No one really knows.

With the controversy surrounding Ryanair's takeover bid, you could be forgiven for thinking that these sort of deals are more trouble than they're worth.

But another hugely successful Irish company - Cement Roadstone Holdings (CRH) - has turned mergers and acquisitions into an art form.

CRH was formed in 1970 through a merger of two leading Irish public companies - Irish Cement Limited and Roadstone Limited. At the time, it was the only producer of cement in Ireland.

It is now the largest company in the country outside of the banking sector.

Since its formation, CRH has relentlessly acquired company after company in order to grow the business, diversify into new products and enter new territories.

Its first acquisition in Europe was Van Neerbos, a Dutch builders merchant, in 1973, and its biggest deal came in August this year with the €1 billion purchase of US construction company Apac.

Cement may not seem like the most exciting thing to invest in, but if you had bought the equivalent of just €100 worth of CRH shares back in 1970 (and reinvested all dividends), by the end of last year your shares would have been valued at around €50,000.

Mind you, the company does work hard to avoid hostile bid situations, preferring to agree terms with its targets.

As for the ongoing Ryanair-Aer Lingus saga, most people would love to flick straight to the last page of this chapter in Ireland's aviation history to find out the ending but, for now, O'Leary is keeping everyone guessing.