Bel, Freddie and Hector verge on breaking the biggest corruption expose ever - a house of cards stretching across London's most influential men - but things get complicated when one of them becomes the centre of a tabloid sex scandal. As they battle against high-level cover-up, Freddie's quest for a controversial contributor takes him right into the lion's den.

It is now November 1956 and The Hour is about to broadcast live and tensions increase for everyone. Bel wants to see the BBC's commitment to impartiality meaning that they cover both the arguments for and against the war in Egypt. Both McCain and Douglas have other ideas though. Freddie has lined up a mystery guest for the show but there is a chance he might not show up. Hector has been sleeping in the office and there is lots of tension between him and Bel following Marnie's visit. Freddie ends up in Clarence's office and is unsure what to do with the information he is given. After when Lix reveals the full scope of Peter and Tom's Egyptian mission, and the real reason for Ruth's death, Freddie is shocked.

Freddie and Bel's bond deepens as they make startling discoveries about the extent of Soho club-owner Cilenti's influence. Yet when a contact's life is endangered, Bel fears they've gone too far. Hector confronts old demons with Laurie - will he upset his team and protect his best friend? Lix and Randall receive uplifting news.

It is now September 1956 and Hector's brilliant interview with Mr Hafiz has caused the fortunes of The Hour to pick up.. The team are invited to spend a weekend at Hector's in-laws. The attraction between Bel and Hector continues to grow and Hector finds it hard to deal with his growing feelings for her, despite Marnie's presence. The suspicion about Tom Kish continues to grow back at the office and Isaacs on the case. Bel is surprised by the sudden appearance of Angus McCain. As the weekend away continues Freddie's crossword continues to baffle him and he believes that there is a hidden code which is an important clue as to who killed both Peter and Ruth.

Bel and Freddie, who work as BBC reporters, are given the chance to escape from their boring jobs to run a topical weekly show instead. With only one of them being able to be the producer, and with Bel in pole position for the job, Freddie is not happy. After a debutante and a childhood friend end up asking him for help in investigating a murder, he ends up realising that the only way he can investigate it is to join the staff of The Hour.

With Freddie gone, Bel struggles to keep The Hour afloat as the new Head of News arrives.

It is now October, 1956 and Freddie is celebrating his birthday. The after effects of Tom's death are still being felt in the newsroom. Even though it was said that Tom had suffered a heart attack, MI6 are now a regular presence in the newsroom and it seems that Freddie in particular is being watched. Freddie goes to see Tom's widow, Jane and after realising that that she was the one behind the camera in Ruth's film, Freddie believes that she could hold some important information. Isaac believes that his latest idea for the programme could bring Sissy closer to him.

It is Christmas at Lime Grove and a time for much soul-searching. Kiki has gone missing and Hector's self-destructive behaviour spirals as Bel and Freddie search for the truth about what happened to her. Meanwhile, Randall tells Lix the real reason for his return but is she willing to dredge up a painful past?