The cast is Gerard Horan, Tracie Bennett, Claire Harry, Alison Pettitt and Carl Rice and it is directed by Toby Swift.
The summary from the BBC Programmes page is:
Now living abroad, Steve discovers his estranged son Matt has been killed serving in Afghanistan. He returns to England anxious to do the right thing. But how do you begin to grieve for a child you never really knew?
Update:
The Daily Mail ★★★★ "A tough and moving drama"
The Independent "Pick of the day"