The prohibition era period gangster drama Boardwalk Empire is set in the 1920s and has received much acclaim since it first hit our screens back in 2010. But where season three of Boardwalk Empire was all about the destruction of Nucky Thompson's world, season four was all about building it up again.

Here's our review of HBO Boardwalk Empire season four. Warning: full spoilers follow.

Even though new opportunities presented themselves for Nucky, like the prospect of opening up more bootlegging in Florida, the people around him would inevitably crumble.

Jimmy's story

Jimmy's story was probably the most noteworthy and his death left fans of the show feeling as though a small void had been created in their viewing lives. After all, Jimmy was not just the show's number two character behind Nucky, he was probably its most interesting and easy to love.

But despite Jimmy's demise, we were still left with Gillian and Harrow. The former wasn't always easy to love and her reasons for doing things were ultimately dictated by her traumatic past, so we always understood her motives.

The gentle monster

Harrow, however, was a character who could very easily be liked. Wearing the scars of the war on the outside, he was frequently ostracised because of his appearance and soft-spoken manner. We still don't know if his demeanour was natural or as a result of his horrific injuries, but either way we grew to appreciate it.

But how on earth could we allow him to be such a ruthless killer and yet still appreciate his presence in the HBO show at the same time? The answer lies in the people he killed: they were either individuals who posed a threat to his family and loved ones, or lowlifes who were going to wind up dead anyway.

However, season four portrayed the enormity of his past sins slowly catching up with him and the gentle monster's conscience steadily getting the better of him. Harrow's death was an event that while shocking and saddening, we were all prepared for well ahead of time - it was inevitable.

Nucky's most dangerous situation this year came from Eli and is another storyline that underlined betrayal as the most prominent theme this season - although on further analysis it's probably the most prominent theme every season!

Chalky's biggest storyline

True to form, however, it was another minor character (i.e. not Nucky) that had us rooted to his developments. Chalky was given his biggest storyline to-date but in keeping with the show's tradition, he would ultimately lose everything. This was mainly in part to his lust for an old love interest - a singer played by Margot Bingham.

Ironically, Nucky was almost brought down the previous year by a similar issue, which made his frequent lecturing of Chalky even more hypocritical and Chalky's effective retirement even more poignant.

Overall, HBO Boardwalk Empire Season 4 is continuing to captivate audiences and bring in the ratings. Despite its tendency to focus on building strong storylines for its more minor characters, we still find ourselves heavily involved with Nucky's business dealings. Boardwalk Empire Season 4 picked up where season 3 left off and gave us a heightened viewing experience once again.