A young man, not long out of his teens, walked to a concert venue carrying an explosive device designed to cause maximum damage to a large number of human bodies, his own included.
He had chosen the softest of soft targets - a pop concert that attracted a mainly young audience. He detonated the device as people were leaving the venue. The blast and the shrapnel killed and injured dozens of those softest of soft targets.
Of the 8 people who have been identified as being dead at the time of writing this, 7 are women and girls. The youngest was just 8 years old.
In carrying out that act of appalling cruelty, the young man had to overcome two deep human senses - self-preservation and empathy towards other human beings.
His preparedness to die and his inability to empathise with his victims were probably rooted in both a belief in an afterlife full of rewards for what religious ideologues define as acts of faith, and in a disconnection from, and disillusionment with the society in which he had lived his whole life.
It's likely that a further ingredient in that already corrosive mix was a vicious misogyny that finds ready succour in fundamentalist sects within patriarchal religions.
Judged by any rational and humane standards, the killing and maiming of the defenceless and the young, is as counter-productive, cowardly and dishonourable an act as it is possible to imagine.
We are all entitled to ask what sort of god is it that demands such a cruel sacrifice as proof of faith?
The truth of course is that a vengeful, bloodthirsty god is both the creation and the reflection of vengeful bloodthirsty and power-hungry men who seek to elevate and justify their actions with the notion of divinely ordained right to take an eye for an eye. The British state kills defenceless young Muslims by dropping bombs on them, ergo it is justifiable for Muslims to kill defenceless young British people in retaliation.
In order for a person to take that vengeful path and to stay on it to its bloody end, they either never had or have switched off the connection to other people's emotions and states of mind that marks us as properly formed social beings - as fully human.
It's probable that this young man had been exposed to people who systematically stripped him of any empathy he had and filled in the resulting hole in his being with bitterness, intolerance and hollow certitudes.
But, I have to wonder whether, for that to happen, he must already have been a deeply flawed person. There are many people in his situation who feel deep anger and bitterness towards those they see as oppressors but who could never carry out such an atrocity.
I find it hard to express how I feel about the sort of people who are easily manipulated by patently absurd propaganda - whether that be religious or political, who have a deformed sense of self and a crude and one-dimensional world view. I understand and deplore the social conditions that led to some of them becoming so morally and psychologically malformed. I might even feel pity for them - but probably not - their actions are just too awful and the consequences of them are too far-reaching.
The consequences of their actions are not confined to the immediate deaths and injuries they inflict – they also serve to support the interests and extend the influence of malign men who would destroy the whole world rather than yield even a little of their power or budge an inch from their ideological position.
So, while I reserve my deepest loathing for the puppet masters who manipulate others from places of comfort and safety – I cannot forgive their puppets.
And in case you think I am speaking only of radical Islamists - I draw no clear distinction between the likes of this morally defective young man and the pilot of an attack helicopter who guns down civilians in an Iraqi street, or the operators of a drone that slaughters civilians at a Yemeni wedding.
They are all props holding up a global system, run by corporate cowards and political poltroons, that depends on bringing out the very worst in people.
The way to counter that malign influence is to strive to bring out the very best in ourselves.