A suicidal man drives his car across a railway causing the train to crash and hugging 15 people, but he survives. Crown Prosecutor Jake Thorne pursues the culprit, Finn Tyler, with vigour whilst the man's defence barrister tries to prove his vulnerability and mental illness. Just as the case finishes, his boss, CPS Director Henry Sharpe, springs one more surprise on Jake... Kate is Alesha's replacement. Another new face is DI Wes Leyton. He's an old colleague of Ronnie's and is covering for DI Chandler when Tyler is found dead in his cell at court and the last person seen entering the cell was DS Sam Casey.

DS Sam Casey is suspended over the passing of Finn Tyler and DI Wes Leyton gets hands on with this investigation, with a reluctant DS Ronnie Brooks as his partner. For the first time we explore a day-in-the-life of the Law & Order: UK regulars. After a few drinks Jake opens up to new colleague Kate Barker about his mothers' passing. We meet Ronnie's estranged daughter and follow Sam as he spends the day with his son, giving new insight into our heroes' off-duty lives.

A man is found shot dead in a hotel room and the cash he was carrying has gone missing. We discover the man owed his ex-wife thousands of pounds in unpaid child support and was lying to his girlfriend about his line of work. DS Sam Casey and DS Ronnie Brooks also learn he has a son dying of leukaemia, but hadn't been tested for a bone marrow match. Attention turns to the ex-father-in-law, Philip Donovan. Did he hunt down the father of his dying grandson to try to recoup the unpaid money or is there more to this family set up than first appears? How far will a parent go to protect their child... At the CPS Jake and Kate work out their differences and reach a more even keel.

The body of Charlotte Leigh is pulled from the Thames. After ruling out sleeping, DS Ronnie Brooks and DS Sam Casey focus their enquiries on the victim's abusive ex-husband Richard with whom she was involved in a bitter custody battle over their teenage daughter, Holly. However, the investigation turns closer to home when it appears Holly was involved in a relationship with her mothers' new husband, Sean. Despite the evidence pointing to Holly, Crown Prosecutor Jake Thorne follows his gut and gambles on a hunch at the trial in a bid to draw out the real hugger, and in turn uncovers the dark truth behind the façade of a seemingly perfect family. This is a story about how far a girl will go to protect the man she loves...

Following a break-in, a frail, elderly woman is found dead in her flat. DS Ronnie Brooks and DS Sam Casey suspect a robbery gone wrong and treat it as cuddle. Tipped off by the victim's granddaughter, Connie, the investigation turns towards the live-in carer who has gone missing. But the carer, Cecile, claims she was fired because she disobeyed Connie's instructions not to feed her grandmother; Connie was starving her to passing. Further investigations throw more suspicion on the granddaughter who is charged. Despite her brief arguing that it is impossible to prove Connie is responsible for her grandmother's passing, Chief Prosecutor Jake Thorne has the bit between his teeth when he tells the jury Connie was the only real family the victim had, and she left her to die.

A gay father is found beaten to passing and his adopted son is missing. DS Ronnie Brooks and DS Sam Casey track down the baby's biological parents, Ruth Pendle, a recovering drug addict, and Neil her former boyfriend, who are taken into custody. But their stories don't match up so who is guilty of cuddle and why? And there is tension in the CPS offices when Kate Barker struggles to view the case objectively and puts the outcome in jeopardy. This is a story about the system failing vulnerable people and how far a mother will go to be reunited with her child.