Pictured: Buncrana pier tragedy baby sound asleep in the arms of her saviour Davitt Walsh
Imagine you didn't know the story behind this photograph. All you would see is a young man tenderly holding a baby, gazing down at her in wonder as she sleeps safe and sound in his arms.
A father and daughter, perhaps; or an uncle and niece.
A lovely picture, you might think, the sort of snap you'd see in a thousand family albums, nothing unusual.
But this picture is different, and the story behind it is so searingly powerful it is almost beyond belief. The man holding the baby is a stranger, no relation to her at all. Yet, because of the events of last Monday in Buncrana, when he saved this helpless child from certain death by drowning, there is an extraordinary connection between the two. It is real, it is unforgettable, and it will last for both their lifetimes.
The mind reels from the horror of that day. When Davitt Walsh leapt into the waters of Lough Swilly and took little Rioghnach-Ann in his arms, lifting her from the water as the rest of her family perished, he didn't save just one life. He also gave Rioghnach-Ann's mother Louise, who has suffered almost unimaginable loss, a reason to carry on.
I don't know how you continue when your partner, your sons, your mother and your sister are wiped out in one brief moment.
How you open your eyes every morning and start the day, how you put one foot in front of the other. But if there is anything that could sustain you, I imagine that it must be your remaining child - this small living, breathing scrap of humanity - miraculously returned to you when everyone else has been taken away.
Of course, the four-month-old baby is oblivious to the enormity of the tragedy. She sleeps sweetly, blissfully, in her rescuer's arms, in the way that only babies can.
Although she was right there as those terrible events unfolded, she will have no memories of the accident. As she grows up, she will learn about what happened.
She will hear about her lost family: her father, her brothers, her grandmother and her aunt. The reverberations of that loss will echo down the years.
Davitt Walsh may not be bonded to Rioghnach-Ann through blood, but the relation between the two is almost as profound.
In the midst of death and devastation he gave her the gift of life - and he gave her mother the gift of hope.
There is nothing greater that one human being can bestow upon another.