Susan Lewis, a young woman scheduled to participate in a beauty contest the next day, goes to bed early after taking a heavy sedative. The next morning, she discovers she is only person left in her village - the entire population of Hambledown has disappeared over night! This case is so strange that the local authorities immediately ask for the Department to take over. As Sir Curtis points out to Stewart, "Your Department is getting quite famous!"Thus, with virtually nothing to go on, the three investigators travel to the deserted village and set up their HQs in the pub belonging to Susan's father. Stewart and Jason set out to check the surrounding areas, while Annabelle runs her research and finds evidence of some missing paint. Meanwhile, Susan is lured to a doctor's office and given an injection... once the detectives realize this, they rush her to a hospital, where it turns out that the injection was completely harmless - nothing but water.As if this wasn't strange enough, they also discover a burnt patch of grass, and wonder what was burnt and why... Jason theorizes that if it were known that another person was 'left behind' in the village that night apart from Susan, the perpetrators would have to make a move... so Stewart sets himself up as bait. The plan works, up to a point, but when the gangsters show up, they knock out Jason and force Stewart to 'accompany' them at gunpoint... which leads him much closer to the case's solution, yet also into danger, and ultimately, in Jason's words, to "a marvelous twist at the end!"

A passenger plane approaching Heathrow Airport request auto-land procedure, and the air traffic controllers can't understand why. When the plane finally lands, it turns out to be completely empty, with neither passengers nor crew aboard... So the Department is called in.In research, Annabelle discovers the picture of a reclusive CEO boarding the plane, but his name doesn't appear on the passenger list. Meanwhile, Stewart finds the body of the flight's pilot in a warehouse that belongs to the CEO's company. Ultimately the clues lead the Department S team to Ireland - and into danger...

When a real estate agent shows a warehouse to a potential client, they discover a replica of an elegant room, with the painting of a lady on the wall, and a crazed young man locked inside, next to the body of a woman. The British police don't know what to make of it, and the Department takes over.Stewart and Annabelle visit the young man in the psychiatric hospital he was taken to and try to get anything useful out of him, but the only real clue they get is the name of a woman - 'Selina'. This remains the only clue they'll get from him, since he is murdered soon after the detectives leave.Meanwhile, Jason tries to find the original of the woman in the painting and locates the artist who painted the picture, but is knocked out and can't prevent the evidence from being burned. Eventually the investigators find the original of the elegant room, but even then the case is far from solved...