You are an Irish Ferries employee working the route from Cherbourg in France to Rosslare, Co Wexford.
While checking boarding papers in Cherbourg one day, an African man presents himself with a passport and an Irish visa which strike you as potential forgeries.
You know this because you and your colleagues have been trained since last November to recognise false travel documents by the Garda National Immigration Bureau.
You alert your superiors and the man's documents are indeed shown to be forgeries. He is not allowed to travel and remains in France.
The man presented himself to you as a tourist, but he is actually an asylum-seeker whose life has been threatened by armed paramilitaries in his home country because of his membership of a certain clan. He resorted to the services of a trafficker to escape the country.
He has a strong case to qualify as a refugee - defined in the 1951 UN Geneva Convention as someone with a "well-founded fear of being persecuted for reasons of race, religion, nationality, membership of a particular social group or political opinion".
People granted refugee status are allowed to live and work in the State and eventually apply for citizenship.
The African man wants to claim asylum in Ireland because other people from his clan are already there and the only European language he speaks is English.
This account is fictional, but it represents the worst case scenario which four leading bishops are today expressing grave concerns about.
The bishops say the Cherbourg controls constitute a "glass wall of exclusion" aimed at keeping out of Ireland all travellers with inadequate documentation, even if they include asylum-seekers whose right to seek protection in another state is internationally recognised.
They are not denying that Ireland has a right to regulate its frontiers, but argue instead that the authorities have established an "outer frontier" in Cherbourg, choking off the inflow of asylum-seekers. And they say the planned introduction of substantial fines for carriers transporting undocumented migrants will make this frontier even more impenetrable and drive people into the hands of people-smugglers.
In their document, No Entry; Carrier Sanctions and the Pre-emptive Exclusion of Asylum- Seekers from Ireland, the refugee committee of the Irish Bishops' Conference make strong moral and legal arguments against such practices.
Official figures show the number of people seeking asylum at Rosslare has dropped dramatically since stricter controls were introduced. Only 24 people claimed asylum there in the first five months of this year, compared to 514 for the same period last year.
The Department of Justice has insisted that anyone who arrives in the State seeking asylum is automatically allowed to enter, regardless of documentation. Under international law, people fleeing persecution are not debarred from seeking asylum just because they have false or forged documents.
But what good is such a reassurance for the man left stranded in Cherbourg if it's the state of his documentation that prevents him from getting to Ireland in the first place?
The Minister for Justice has pointed out that asylum-seekers are, of course, entitled to make their asylum application in France or any other EU state through which they first entered the EU.
Indeed, under the Dublin Convention agreed between EU states, asylum-seekers are supposed to make their claim in the first EU state they enter.
Almost by definition anyone who makes it to Irish shores must have been transited through another country, unless they have arrived on a direct flight.
The aim of the convention is to prevent "asylum shopping" between EU member-states. While in theory it allows EU states to return asylum-seekers to the first member-state they entered, in practice it has proved difficult to implement.
However, Irish authorities seem to be citing the Dublin Convention to legitimise the Cherbourg checks as well as the planned carrier sanctions.
But human rights groups and the bishops counter that not all countries apply the same high standards as does Ireland in assessing claims for refugee status under the Geneva Convention.
For France, as well as Germany and Italy, only persecution by the state the person is fleeing warrants protection under the Geneva Convention. So anyone fleeing persecution in these countries by non-government forces such as paramilitaries, neo-Nazi groups, guerrillas or religious fundamentalists could be deported back to their country of origin.
Ireland, however, along with many other states including Britain, the US, Australia and Canada, accepts a fear of persecution by other groups, even if not encouraged or tolerated by the state.
A recent unanimous ruling by the British House of Lords stopped the authorities there from bouncing back to France and Germany asylum-seekers who passed through those states in transit to Britain. The court said they were not "safe" countries to which people claiming persecution from non-state forces could be returned as they were likely be deported back to the country they were fleeing.
So the man in Cherbourg may risk being sent home if he makes his claim in France, whereas if he managed to cross the channel and make it on to Irish soil, he could be among some 7 per cent of people recognised as refugees and allowed remain in the State.
Such an issue has not been tested before the Irish courts, but given the similarity in the legal systems of both jurisdictions, the bishops say it is not unreasonable to suppose that an Irish court might arrive at a similar decision.
Amnesty International in Ireland has said the Geneva Convention on refugees is "rendered meaningless if people in search of protection cannot reach the territories of places like Ireland".