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....

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.

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.

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.

The Watsons are no strangers to sibling placements, but when Casey takes the call from her supervising social worker one frosty January morning, she can instantly tell from the tone of her colleague’s voice that there’s a complicated case ahead. And she’s right. A four-day-old baby boy called Tommy - born in prison - plus his four-year-old half-brother, the lively Seth. A month later, the very moment she gets out of prison, the boys’ mother - a 19-year-old called Jenna - also follows.

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.

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'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.

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.

Angie, 6, and sister Polly, 4, are utterly distraught when they arrive to stay with foster carer Cathy Glass. Their older half-sister Ashleigh has accused their father of rape, and the two young sisters have been removed from home to keep them safe. Cathy tries to comfort the girls, but they are inconsolable. They just want their mummy and daddy, who they love dearly. The girls appear to have been well looked after, but as they settle and start to talk of life at home, it becomes clear something is badly wrong.

From the author of Number One bestseller Damaged comes the poignant and shocking memoir of Cathy's recent relationship with Tayo, a young boy she fosters whose good behaviour and polite manners hide a terrible past. Tayo arrives at Cathy's with only the clothes he stands up in. He has been brought to her by the police, but he is calm, polite, and very well spoken, and not at all like the children she normally fosters. The social worker gives Cathy the forms which should contain Tayo's history, but apart from his name and age, it is blank.

When Stevie’s social worker tells Cathy, an experienced foster carer, that Stevie, 14, is gender fluid she isn’t sure what that term means and looks it up. Stevie, together with his younger brother and sister, have been brought up by their grandparents, as their mother is in prison. But the grandparents can no longer cope with Stevie’s behaviour, so they place him in care. Stevie is exploring his gender identity, and like many young people he spends time online. Cathy warns him about the dangers of talking to strangers online and advises him how to stay safe.

From the author of Sunday Times and New York Times best seller Damaged, the gripping story of a woman caught in a horrific cycle of abuse - and the desperate lengths she must go to in order to escape. When Aisha spots an ad for a 'personal introductory service for professionals' in the newspaper, she could never have guessed it would lead to such a perfect marriage. But you should be careful what you wish for.... Mark is sorry the first time he hits Aisha.

Cruel to Be Kind is the true story of Max, age six. He is fostered by Cathy while his mother is in hospital with complications from type 2 diabetes. Fostering Max gets off to a bad start when his mother, Caz, complains and threatens Cathy even before Max has moved in. Cathy and her family are shocked when they first meet Max. But his social worker isn't the only one in denial; his whole family are, too.

Nine-year-old Archie and his five-year-old sister, Bobbi, are taken into emergency police protective custody after an incident of domestic violence at their family home. Rosie collects the children from their out-of-hours foster carer on New Year's Day and instantly recognises Archie from a domestic violence workshop she helped with. Rosie remembers that when asked what he enjoyed most about the course, Archie said, 'The biscuits'. Social workers are concerned that Archie and Bobbi have been neglected.