A virulent flu bug is spreading through the country like wildfire. Abby Grant (Carolyn Seymour) and her husband David (Peter Bowles) are aware that the flu has reportedly claimed millions of people's lives in China, but they don't think that could happen in England. Abby becomes ill and takes to her bed. Meanwhile Jenny Richards (Lucy Fleming) learns from a doctor that this is no flu bug and that hundreds are now dying. Acting on his advice she flees London for the countryside. Abby wakes days later and fears that she may be the only one left alive...

Abby meets Arthur Wormley who has some strong ideas about how the survivors of 'the death' should organise themselves. Meanwhile Greg Preston (Ian McCulloch) meets a strong willed woman called Anne (Myra Frances) who needs his help to rescue a man who is trapped under a tractor in a nearby quarry. Elsewhere Jenny is still wandering the countryside alone...

Abby, Jenny and Greg have made an abandoned church their base. Abby hopes to find her son Peter. They make a trip to a nearby supermarket to gather some food supplies and encounter some of Wormley's men who insist they leave their loot. Jenny and Greg overpower them and they escape. The men are intent on revenge and begin to search the countryside for the trio...

Abby, Greg and Jenny are still searching for Peter. Greg and Jenny are becoming closer. They meet a man called Charles Vaughan (Denis Lill), a self-sufficiency expert, who has sobering theories about the number of survivors of 'the death' and their prospects for the future. He invites them to join his community, but it soon becomes clear that he has a hidden agenda which could involve Abby...

Abby is still searching for Peter and returns to his school. Meanwhile Jenny and Greg meet two children, John and Lizzie who are keen to join them. They have a lead which may help in the search for Peter. Before 'the death' some individuals, who were nicknamed 'the angels' by the press, foresaw the impending catastrophe and isolated themselves. It is thought that some of the boys from the school went to find them. Jenny, Greg and the children make an abandoned house their base, whilst Abby sets off to find 'the angels'...

Abby becomes separated from Jenny and Greg and rescues a man called Jimmy Garland (Richard Heffer) who is waging his own personal war against a man called Knox (Peter Jeffrey). Garland is heir to the Waterhouse estate that Knox has taken over and he wants it back so he can lead the community that has started there. Abby is captured by Knox and he tries to convince her that Garland has aggravated the situation and that he is willing to co-operate...

A young woman called Wendy (Julie Neubert) and an old woman called Emma (Hana Maria Pravda) have foraged since 'the death' but are now going hungry. Wendy meets Tom Price (Talfryn Thomas) and steals his food. Abby meanwhile rescues Emma from a pack of wild dogs, whilst Greg, Jenny and the children draw them off in their minibus. Tom wants his revenge on Wendy but doesn't reckon on Abby's presence. Meanwhile Greg and the others arrive at a deserted country grange, which may be just the place they need...

When agricultural expert Paul Pitman (Christopher Tranchell) arrives at the grange, Greg feels threatened but the others welcome his expertise. When Greg remembers the supplies in the quarry (Genesis), Tom and Barney are sent to fetch them. Two more survivors arrive, former company director Arthur Russell (Michael Gover) and his secretary Charmian Wentworth (Eileen Helsby) who has stuck with him since 'the death'. Arthur's attitude infuriates Abby. When Tom and Barney fail to return, Greg and Paul set off after them in Arthur's landrover...

Petty arguments are dividing the ever growing community at the grange. Abby decides on a party on May Day as a remedy. The pary goes well and spirits are raised. However, the next morning they awake to discover that one of their number has been brutally murdered. The community meet to decide how to deal with the person they believe to be the murderer...

A pregnant young woman called Laura arrives at the grange, seeking shelter from her partner, a man called Huxley, who wants her back but doesn't want her unborn child. Abby and Greg argue as to whether she should be allowed to stay. When John and Lizzie unknowingly give away the fact that Laura is staying at the grange, Huxley embarks on a series of reprisals until the community agrees to give up Laura to him....

Crippled Vic attempts to commit suicide because he is feeling increasingly useless. Greg tries to convince him that his teaching of the children is an important job. When Anne Tranter arrives at the grange she is shocked to discover that Vic is alive and that Greg therefore knows of her heartless actions when they first met (in Genesis). When Vic learns that Anne is actually staying at the grange he becomes intent on ultimate revenge...

When a flood destroys both their crops and stores, the survivors decide to trade the petrol in the tanker driven there by Donnie and Anne, as its the only thing of value they have left. Greg and Jenny set off in the tanker to trade with a nearby settlement. However they are followed by a man called Lawson and his two cronies, who want the petrol for themselves at any cost...

Abby is tiring of life at the grange and her thoughts turn to resuming her search for her son. After a row with Greg over the taking in of a sick girl, Ruth. Abby sets off for Waterhouse to find Jimmy Garland. Meanwhile Greg and Arthur make their first attempts towards federating the communities that have sprung up since 'the death'. When Ruth recovers, Greg and Jenny discover she is a former medical student and that she has some startling news for them...

Greg travels to a community at Whitecross to trade with its leader Charles Vaughan (Denis Lill) who he last met at Mardell. Jenny is now pregnant so Greg also seeks news of Ruth's whereabouts, as she promised to return to help with the birth. Whilst Greg is away, a fire destroys the grange. The survivors of the blaze are soon reunited with Greg, who leads the way back to Whitecross where they hope to stay, at least until Jenny has had her baby...

When there are complications after the birth of Jenny's baby, Ruth knows that the only course of action is to locate some medicine to treate her. Paul, who is now in love with Ruth, elects to go on the dangerous journey into Birmingham to find what Ruth needs. Eventually Paul returns, but he reveals that he doesn't fell too well. Ruth isolates Paul in a barn to prevent the possible spread of infection and begins to treat Jenny whose condition has worsened...

A couple called Penny and Amul arrive at Whitecross claiming to have news of Abby. Ruth goes with them thinking her medical skills are needed at the place where Abby is staying. She soon learns that she is being taken to London instead to help nurse the sick there and that Abby has already moved on. The large settlement in London is run by a man called Manny who does not want Ruth to leave. When Greg and Charles fear for Ruth's safety they journey to London to rescue her...

Greg and Charles arrive at the London settlement and are reunited with Ruth. She tells them she can't leave the sick there and come back to Whitecross, especially as her assistance will be needed if the community is to be re-located to the Isle of Wight as planned. When Ruth learns from Nessie that Manny has no intention of taking the community out of London, she agrees to an escape attempt with Greg and Charles...

A man called Alistair arrives at Whitecross and considers the possibility of staying there permanently. He hides the fact that he is a convicted child killer because he feels that he is a different person now and has paid the price for his crime. Unfortunately Hubert finds a newspaper clipping belonging to Alistair which details his past. He passes the information on to others. When John goes missing, Alistair is immediately suspected...

When Mina (Delia Paton), an eccentric member of the community at Whitecross, spurns Hubert's unwelcome attentions, he begins to spread vicious rumours that she is a witch. When John and Lizzie see Mina bake a clay figure representing Hubert and Pet and Peggy add up other recent events, they begin to believe that Hubert may be right......

Charles and Greg hold a meeting at Whitecross with leaders of nearby settlements to try to come to some co-operative agreements. The event is interrupted by the news that the wife of one of the leaders has been killed by a sniper. It is soon learned that the sniper targets young women and seems to be travelling towards Whitecross. Jenny, bravely volunteers to act as bait to bring the sniper out into the open...

When a former vicar, Lewis Fearns (Roy Herrick), arrives at Whitecross and reveals his occupation, community life is disrupted. Charles becomes worried that the distractions caused by Lewis may be very damaging given the hard work that is required to sustain the settlement. Is there a place for God and a return to religion in the new order of things..?

Charles and Pet are returning from a salt collecting expedition when they meet two other travellers who become very ill. They take them to a nearby settlement in an old army camp. The community there is run like a police state where eugenics, euthansia and religious fervour all hold sway. The people there are led by a charismatic man called Max Kershaw and his second in command Joy Dunn. Pet is fearful that they may not be allowed to leave, whilst Charles is summoned to speak to the community's council...

Mina befriends a man called John Millen and arranges to meet him at Whitecross at a later date. When John fails to arrive and two other men come to the settlement on his barge (one of them wearing John's hat) Mina fears the worst. Charles and Greg welcome the men, Kane and Grice, but also have misgivings about their intentions. Pet is suspicious too, as she recognises Kane from before 'the death'...

Ruth invites members of a failed community to join the Whitecross settlement, despite the fact that they have been exposed to a disease. When Arthur and Jack contract the illness she fears she may have made an error in judgement. Meanwhile, the self appointed leader of the young new arrivals, Mark Carter (Ian Hastings), advises Charles on where he is going wrong agriculturally and draws up a new plan for him to examine...

When Sally becomes pregnant by Alan, Charles is overjoyed, thinking this will encourage a baby boom at Whitecross. Sally wants to live with Alan as his wife but he has other ideas. As the situation becomes more tense, Charles crosses swords with Melanie, Ruth and even Pet...