Part 2

The second part is where the operation starts killing the wrong people. Harry Brown is established in the Falls Road and in a relationship with Josephine Laverty when two separate hunts begin to close on him: the IRA's own security checks on new arrivals, and the police investigation running alongside his own, led by Inspector Howard Rennie.

Brown, working from what he has seen, reports that the gunman was in a local club and that a girl called Theresa McCorrigan knows his name. She is the one person who can identify Billy Downes, and she is arrested.

What follows is the strongest sequence in the serial. Caught between Rennie's questioning on one side and the certainty of what the IRA will do to her family if she talks on the other, Theresa hangs herself in custody without giving the gunman up. The case the police were building dies with her, and the man the government sent to Belfast is no closer to his target than he was an hour earlier.

The part also contains the nearest thing to a thriller coincidence the serial allows. Brown and Downes are in the same club without either knowing who the other is. The club is raided by the British Army, and a soldier recognises Brown and, reading him correctly as an operative, says nothing and arrests Downes instead.

Downes is questioned and released. The sequence sits across the join between the first two parts, which is one of the small uncertainties in the record of this serial, but its place in the story is clear enough: the two men have been within a few feet of each other and neither is any the wiser.

What finally exposes Brown is not his own mistake. Two senior officers, one of them Colonel George Frost, discuss his presence in the city over a meal in a restaurant, and a waiter overhears the conversation and passes it on. From that point the local IRA leadership begins checking every new arrival in its areas, and Brown's cover starts to run out.

Linda Robson's work as Theresa gives the hour its weight. She plays a girl who did a favour for a man on the run and has no way to escape the consequences, and the episode does not soften her death into rhetoric or explain it with narration. Sean Caffrey's Rennie is the other significant performance: a police officer doing his job properly and finding that the law is the least of the pressures on the person in front of him.

Both of the episode's turns depend on someone standing in the right place at the right time, the soldier in the club and the waiter at the table, and neither is prepared for in advance. That is a structural shortcut the serial takes twice, and the second hour is where it is most visible.

Against it, the part has a genuine understanding of how security work grinds down the people who are not playing, and it makes the audience feel the cost before it makes them feel the loss. By the closing credits the IRA knows a British officer is in the city, Brown does not have a name to go with the man he is hunting, and the third part has everything it needs.