By Mark Simpson
BBC Ireland correspondent
Inside the McCartney family house there are two constant noises - the dull ring of the telephone and the background chatter of a 24-hour news channel.
Catherine McCartney (right) is a history and politics teacher
For the McCartney sisters, it all feels unreal. What is even more surreal is when their pictures appear on the TV, on the hour every hour.
"Sometimes I wonder to myself 'is this all really happening?'," says Claire, the youngest of the five sisters.
But this is not a dream, it is a recurring nightmare. The McCartney sisters have lost two brothers in the space of four years. First Gerard aged 28, then Robert, 33.
Gerard took his own life after a period of depression. Robert was stabbed and kicked to death in the centre of Belfast. The gang which killed him included at least three members of the IRA.
No ordinary family
He died only yards away from the Hilton Hotel where he and his fiancee Bridgeen were hoping to have their wedding reception in July.
Now their two young sons Conlaed, 4, and Brandon, 2, are left to wonder why daddy does not come home at night. What is also confusing is why so many cameras and microphones are being shoved in front of their mummy.
Brigdeen has told them that their father has gone to heaven. As for the international media presence, in some ways that is more difficult to explain.
The boys are too young to understand the political significance of a Catholic family from a hardline republican area daring to challenge the IRA.
The McCartney sisters have been dubbed Belfast's "Famous Five"
No one needs to explain it to them, but if anyone did try to put it in their language, it would be a bit like the seven dwarfs deciding to take on the Power Rangers.
The IRA are self-styled super-heroes, not used to their authority being questioned by ordinary folk in republican areas. But the McCartney sisters are no ordinary folk.
Strong, courageous, bold, articulate, tenacious and formidable - just some of the adjectives used about them in recent weeks.
Gemma, a 41-year-old nurse, is the eldest. Next comes Paula, who is perhaps the best known of the sisters, because she has done most of the media interviews. A mother of five children, aged 19 to three, she is a mature student at Queen's University, doing women's studies.
'Matter of persistence'
She hasn't been at many lectures recently. In the six weeks since her brother died, Paula's modest home in the republican Short Strand area of east Belfast has become the unofficial headquarters of the campaign 'Justice for Robert'.
Wooden placards litter the porch, leftovers from the recent protest rally urging the killers to give themselves up. In the living room, an old family photo of Robert sits on the TV, which is continually tuned to 24-hour news.
The phone sits in the hall and rings every five minutes. It is normally a journalist. Family members take it in turns to threaten to throw it out the window. No-one ever does.
In the kitchen, cups of tea are drunk as if they are liquid oxygen. Look for a puff of smoke and you will usually find Catherine McCartney, the one with the glasses, and the straight dark hair. Close by her will be a red folder with vital pieces of information, such as the schedule for the planned four-day trip to Washington.
It is all neatly written in a ring-bound file. It is not hard to guess which of the sisters is a teacher.
Robert McCartney, 33, was killed near Belfast city centre
She teaches history and politics - subjects which now swamp all aspects of her life. Catherine understands why the IRA was reluctant to admit its link to her brother's murder, she realises the historical reasons why the IRA did not hand over the killers to the police, but that does not mean she thinks it was right. Quite the opposite.
Donna is the middle sister. She runs a sandwich shop in Belfast. She has kept on working in recent days but it has not been easy.
The youngest sister, Claire, 26, is a teaching assistant. Like the others, she is a confident speaker. She summed up the family's determination to find their brother's killers by calmly telling BBC Radio Four's Today programme: "It is just a matter of persistence."
They have lost count of the number of interviews they have done. The Irish state broadcaster RTE talked to them for an hour last month on the prestigious Mariane Finucane programme. There were tears followed by laughter followed by more tears as they talked about their memories of Robert.
"Ah, we spoiled him," remembers Gemma, "with kisses mainly, because we didn't have any money."
They are an open family. Open enough to admit that many of them used to support and vote for Sinn Fein, including Robert himself.
They are also a close-knit family, and they will need to be. Like all families, there are tensions, strains, differences of opinion but - so far - they have managed to stay united.
Robert McCartney's sisters have put pressure on Sinn Fein
In Belfast, 'the McCartneys' has entered the political phrase book. It does not have the same ring as 'the Clintons' or 'the Kennedys' but there is a connection.
In Washington next week, the five sisters are due to meet Senator Ted Kennedy and Senator Hilary Clinton. They will also see President Bush. It is a measure of how much international support they have gathered.
Much as they appreciate the attention, the bottom line is that these sisters have been catapulted into the international spotlight because their brother was stabbed, kicked, beaten and punched to death.
They've become Belfast's Famous Five, but for all the wrong reasons.