"London... my city. It is a monstrous place..." By now, we're used to this foreboding voiceover at the start of City Of Vice. It's a good way to start because it sets the scene, and you just know that there will be a murder of some sorts for the brothers Fielding and their Bow Street Runners to sort out.

Already in the series, we've seen them investigate cutthroat goings on in a whore house, and erm, some more cutthroat goings on in a molly house. What's in store for us this week? While they are reminded of their duties to protect the rich by their patrons, it doesn't stop them hunting down a murderer in the Irish shanty towns of Covent Garden.

We started last night's episode with Henry explaining that the city, now flourishing and bursting at the seams thanks to increased trade and commerce, had spawned a new kind of class – people who weren't born into money had suddenly become rich thanks to entrepreneurial business ventures. One of these working-class-made-good, a Scotsman called Anderson, and his daughter had been held at knifepoint and had their sliver stolen. He wasn't willing to speak to the Fieldings about the incident – he was too preoccupied marrying his daughter off to a rich family. Mind you, during the robbery, it was obvious that something more sinister had happened.

Meanwhile, the Fieldings were paid a visit by one of their patrons – a sour-faced young chap – who told them that they were skating on thin ice. The number of break-ins had increased since their 'police force' had been created and he was considering withdrawing their funding and taking these cases to the thief takers. The pressure was on, and the Fieldings were faced with their first crime wave.

So it was back to the scene of the crime, and an interview with Anderson. He was an angry man, and wouldn't tell the Fieldings anything – his daughter was getting married the following week and all he wanted was his crockery back so his house would look respectable to his new in-laws. The Fieldings insisted interviewing the servents, who were mostly Irish. The brothers were swiftly thrown out, but on their way out they met a local doctor. They deduced, by the equipment he was carrying, that he was on his way to administer a pennyroyal abortion.

Henry dispatched the Runners to Seven Dials in Covent Garden (home nowadays to boutique shops, cafes and theatres) to have a look around the Irish slums and ask some questions. Their visit didn't yield much, but it did rattle some cages – the guy we saw at the start of the episode, who had robbed the father and daughter at knifepoint, paid a visit to the Fieldings and held Henry's young wife at knifepoint and told them to keep their noses out.

In a voiceover, Henry said that the virginity of a new bride was absolutely sacred, and any woman who married and was already de-flowered would be considered the lowest of the low. No wonder Anderson wanted to keep things quiet about the abortion – his bloodline and future wealth depended on it.

For Henry, this had become a personal case because of the direct threat to his family, so he took John back to the Andersons to try and get him to talk. They spied through the window an extraordinary sight – Anderson and his daughter having dinner with the future in-laws, crockery and posh knives and forks back in the house.

When Henry and John went in and had a quiet word, Anderson was as taciturn as ever and he explained that one of the Irish servants had put him in touch with the thieves and he had paid them to bring back the stolen goods. John decided to bring out the big guns, and promised that they would bring the men who raped his daughter to justice. With that secret out in the open, Anderson cracked and wrote a letter to the thieves to ask them to bring back the rest of his gear straight away. Henry sent for the rest of the Runners.

Anderson had to get rid of his guests quickly, so he asked his daughter to play a few notes on the harpsichord. This triggered a flashback from her ordeal and she broke down, screaming to her future in-laws, "I've been f*****! I've been f***** and f***** again!" The future in-laws left in a hurry, and Anderson's best-laid plans of securing his and his daughter's future had all but gone.

Meanwhile, Henry and the team were planning the sting. Before the thieves, Anderson and Henry had a touching conversation about family – Anderson explained that his wife and three sons were killed by smallpox, and that his daughter was the only thing left. He also explained, bitterly, that working class people always have to work for their money, and that he had everything ripped away from him once, and now again. Catching the thieves and the men who raped his daughter was not a consolation, he said.

The sting went to plan and the head of the gang was captured, but in a shocking ending, Anderson, a ruined man, poisoned his daughter and slit his own throat.

Not surprisingly, this caused Henry to do some serious soul searching – was this police force experiment doing any good? What was his relationship to his young wife and son? And had mixing it with a brutal gang made them a direct target for all kinds of people? The end scene, where the rest of the gang who got away, tooling themselves up, seemed to suggest so.

This was the best City Of Vice yet. It was REALLY good. The voiceovers were kept to a minimum so the plot moved along quicker, and there was real dramatic tension in this episode (something I thought was missing in the first two). It was also a sad story, and an insight into what it was like to be a parent trying to make something of himself in Georgian London. Great stuff.

Episode one review here.
Episode two review here.