When psychology lecturer and psychic mediums specialist Robert Bridge takes his students to a clairvoyance evening, he meets troubled psychic Alison Mundy. Sceptical about her abilities, Robert decides to study Alison and contemplates writing a book about her after sitting in on one of her readings. But he is completely thrown when Alison claims to see the spirit of his dead son Josh.

An eight-year-old girl goes missing and her distraught parents make an emotional televised appeal. The next day, when Alison says she has seen the child's ghost in the supermarket, the police are deeply suspicious - then they discover a drowned body.

On the ward of a hospital psychiatric unit, Alison meets Daniel, who is being held after an attack on his girlfriend. He desperately tries to persuade Alison that the man responsible for the assault was the other Daniel - Daniel Two. Doctors are convinced the young man is a pathologically violent schizophrenic, but Alison has serious doubts.

On the first day of her new job at an old people's home, Alison finds a photo of Robert's dead son Josh, belonging to his mother, Jenny, and realises that Josh steered her towards the job in another attempt to make some kind of emotional contact with his father. Alison befriends fellow nurse Connor, who is being tormented by the ghost of a former patient, who jumped to her death from a window because he wouldn't help her die peacefully.

Sandra Petch is petrified and thinks that her flat is haunted, but when Alison comes round to try and help she witnesses the terrifying tableau of a man smothering his wife to death. Robert is curious and the three spend the night there, waiting to see what will happen. As Alison falls asleep, she enters a nightmare where she relives the last moments of the murdered woman's life.

Alison thinks that she is being haunted by the victims of the train crash which nearly killed her six years before. But she soon finds out that she is being followed by the survivors of the disaster, who want her to help them communicate with their lost loved ones. Robert and she come into contact with the afterlife in a way that will change their lives for ever.

Alison visits a woman who starts exhibiting symptoms of the disease that her fiance's first wife was killed by, and realises that she is possessed by the dead woman's spirit. Meanwhile, Robert's sudden scepticism baffles Alison, who is unaware of his fatal illness.

A woman called Gemma comes to Alison, asking for her help, after her best friend was killed by a ghost. Alison is sure Gemma knows more about the spirit than she is letting on. But Alison has other things to worry about - her mother's spirit is still around and still cleaning. In the mean time, Robert comes clean to Jude about his tumour.

A father comes to Alison to ask her about a baby monitor that whispers to his child. Alison is sure it is a spiritual event, but the mother isn't so sure. Alison herself, is being contacted by her own mother's spirit and Robert doesn't believe that it's happening. Just when everything seems to have been organised, it gets worse.

With the household being taken over, Alison is unable carry on, and gives into her mother's spirit. Robert decides to contact the psychic's estranged father, who Alison is reluctant to talk to. But sooner or later, she has to deal with her own past, and the death of her mother.

Alison and Robert visit a prison after a series of mysterious suicides take place behind bars. There they encounter a serial killer, who blames a malevolent spirit called the Rat Man on his own murderous spree. As Alison strives to banish the evil from the place to help the other convicts, she puts herself in terrible danger.

When a teenager, who has been haunted by a young boy, claims a psychic he visits is an impostor, Alison tries to sort things out. However, she find that on this occasion, she can't contact the spirit world. Robert still hasn't told Alison of his tumour, but will he ever get the chance, before it's too late?

Alison Mundy is still recovering from the traumatic seance that put her in a coma. She realises that she has dedicated her life to helping the spirits and when she sees one on the roadside, she is determined to find out what has happened. Before long she is entangled in a story that involves a car crash and some friends. But this time, she won't be able to help everyone...

With Robert in a coma at the hospital, Alison rushes to his bedside, finding Jude there, who is less than happy to see her. Whilst in the hospital, waiting, the psychic witnesses a strange nurse wandering the corridors. This is confirmed by many of the workers, who have heard rumours about this unusual being. Why is she there - and does she mean the end for Robert?