Fourteen-year-old Hannah comes to live with foster carer Maggie Hartley after her mum pleads with Social Services to take her into care, unable to cope with her daughter anymore. Previously a good student, a loving daughter and sister, Hannah is now playing truant, drinking and taking drugs. Angry and mistrustful, it seems that nobody can reach this troubled teenager.

A 5-year-old boy, Ethan, is brought to Casey in the middle of the night after the sudden death of his young mother after a drug overdose. Estranged from her parents, Ethan’s mum had been abused by her ex-partner, and began taking drugs to cope. Ethan is obviously lost and bewildered, and regularly wakes up screaming for his mum in the night. He begins to lash out at other kids at school and his behaviour becomes more volatile. 

It's the night before Christmas when Casey and Mike get the call. A 12-year-old girl, stuck between a rock and a hard place. Her father is on a ventilator, fighting for his life, while her mother is currently on remand in prison. Despite claiming she attacked him in self-defence, she's been charged with his attempted murder. The girl is called Bella, and she's refusing to say anything. The trouble is that she is also the only witness....

Damian is just seven when he is taken in by foster carer Cathy Glass. His mother, Rachel, loves her three young children dearly, but she is vulnerable, naïve and unable to cope on her own. Cathy sets about helping Damian overcome his eating issues, with the hope that he will eventually return home. But when Rachel’s new boyfriend, Troy, arrives on the scene, Cathy becomes deeply concerned. She soon realises that Damian and his siblings are in great danger.

It's late on Friday night when Casey's mobile starts to ring. She is expecting it to be her daughter, Riley. But it isn't Riley. It's a woman from the Emergency Duty Team. So begins Casey and Mike's latest fostering challenge - a 15-year-old girl called Keeley who's run away from her long-term foster home 25 miles away.

After taking a few weeks off work, Casey is presented with a new foster child: 14-year-old Elise, whose Mum left her at just five years old. At first, she’s no trouble at all, that is until she falsely accuses another carer, Jan, of acting inappropriately towards her. It turns out this isn’t the first lie Elise has told—her previous carer was constantly following up allegations Elise had made of people bullying her, trying to have sex with her or hurting her physically. 

Brought to Casey as a short-term emergency placement, 14-year-old Adrianna arrives with nothing but her gratitude. Having turned herself in to a social services office some 100 miles away, she has no possessions, no English and, apparently, no history - not that she's willing to share, anyway. She is a beautiful young Polish girl, with the bearing of a ballerina, but is terrified, malnourished and unwell.

Just when Casey thinks her foster care duties are done, she’s asked to look after Sam, a troubled nine-year-old with a violent streak who drove his previous guardians to release him of their care. It soon unfolds, however, that this is no simple case. Determined to get to the root of Sam’s behaviour, Casey is committed to uncover his mysterious past only to find out something far darker than she ever imagined.

Harley, 13, has been sectioned under the mental health act after attempting suicide. She was spotted climbing the railings on a footbridge that crossed a busy motorway and pulled to safety by a member of the public. After six weeks in hospital, social services are looking for a short-term placement so she can be kept safe while family therapy takes place. Harley has a family - a widowed mother and an older sister, Milly, who left home with her long-term boyfriend just over a year ago. 

Casey Watson is back, doing the job she does best - rolling up her sleeves and fostering the children who, on first meeting, seem like hopeless cases. But when she meets Miller and discovers the truth about his disturbing childhood, even Casey begins to doubt if this child will ever be able to accept love. Found naked and alone on a railway track, Miller was just five when he was first admitted into the care system. 

Casey's Unit is, as ever, full of troubled, disaffected pupils, and new arrival Leo is something of a conundrum. Thirteen-year-old Leo isn't a bad lad - in fact he's generally polite and helpful, but he's in danger of permanent exclusion for repeatedly absconding and unauthorised absences. Despite letters being sent home regularly, his mother never turns up for any appointments, and when the school calls home she always seems to have an excuse.

Six-year-old Amelie lives with her mother, Kelly, who suffers from bipolar disorder. After Kelly attempts to burn down their family house, it becomes clear that her daughter is in grave danger. Amelie is quickly taken into care. When she arrives with foster carer Casey Watson, Amelie acts much younger than her age. Casey must get to the root of Amelie’s behaviour, while doing what she can to keep the family together. Will Amelie ever find the safety of home?

Experienced foster carer Rosie Lewis takes on the heart-breaking case of Megan, a baby born with neo-natal abstinence syndrome and a cleft palate. Addicted to drugs from birth because of her mother's substance abuse during pregnancy, new-born Megan is taken into Rosie's loving care. Rosie is supposed to help Megan find her new permanent home, but it turns out that Megan has already found her 'forever mummy' in Rosie.

After a horrific car crash, two parents are left dead, and a young girl is fighting for her life in hospital. When 13-year-old Louisa wakes to find that her loving, happy family has been shattered overnight, she is forced to seek comfort in the arms of a stranger. But can Maggie find a way to bond with this teenager overwhelmed with anger and grief? And will she regret making a decision that will affect her and Louisa for the rest of their lives?

Ava Thomas knew leaving was the right decision. Trapped and manipulated in her relationship, and after yet another violent beating whilst she was pregnant, Ava was helped to a women's refuge with her children. Listening to the stories of other women there, Ava began thinking back to where it all started to go wrong. Brought up by a mother who never loved her, Ava sought that missing care and warmth elsewhere. Running away to her father's home as a teenager, she thought she might finally be safe. But after being abused by her own brother, she was thrown out onto the streets.