It quickly become obvious that all their evidence is second hand. They have evidence (such as birth certificates) and what other people tell them. But there is always a possibility that there mother really isn't their mother. Maybe she's their grandmother and their sister is their mother. Or maybe they're adopted. It's a good opening to issues of knowing what is true and the different rules different people use to verify truth.
But this story I'm going to link to is even more unlikely. What if your mother is really your biological mother, but she's not who you think she is.
The Guardian has a story Saturday of two Canadian-born, naturalized American brothers, who, well, here's the beginning of the article:
Tim Foley turned 20 on 27 June 2010. To celebrate, his parents took him and his younger brother Alex out for lunch at an Indian restaurant not far from their home in Cambridge, Massachusetts. Both brothers were born in Canada, but for the past decade the family had lived in the US. The boys’ father, Donald Heathfield, had studied in Paris and at Harvard, and now had a senior role at a consultancy firm based in Boston. Their mother, Tracey Foley, had spent many years focused on raising her children, before taking a job as a real estate agent. To those who knew them, they seemed a very ordinary American family, albeit with Canadian roots and a penchant for foreign travel. Both brothers were fascinated by Asia, a favoured holiday destination, and the parents encouraged their sons to be inquisitive about the world: Alex was only 16, but had just returned from a six-month student exchange in Singapore.
After a buffet lunch, the four returned home and opened a bottle of champagne to toast Tim reaching his third decade. The brothers were tired; they had thrown a small house party the night before to mark Alex’s return from Singapore, and Tim planned to go out later. After the champagne, he went upstairs to message his friends about the evening’s plans. There came a knock at the door, and Tim’s mother called up that his friends must have come early, as a surprise.
At the door, she was met by a different kind of surprise altogether: a team of armed, black-clad men holding a battering ram. They streamed into the house, screaming, “FBI!” Another team entered from the back; men dashed up the stairs, shouting at everyone to put their hands in the air. Upstairs, Tim had heard the knock and the shouting, and his first thought was that the police could be after him for underage drinking: nobody at the party the night before had been 21, and Boston police took alcohol regulations seriously.
When he emerged on to the landing, it became clear the FBI was here for something far more serious. The two brothers watched, stunned, as their parents were put in handcuffs and driven away in separate black cars. Tim and Alex were left behind with a number of agents, who said they needed to begin a 24-hour forensic search of the home; they had prepared a hotel room for the brothers. One of the men told them their parents had been arrested on suspicion of being “unlawful agents of a foreign government”.The reporter follows up on many of the questions you're probably asking yourselves. Here's the link again.
This is a great story for a high school class - I can't imagine any high school students who wouldn't be totally sucked into this story and imagining what it would be like if this happened to them. And there are lots of lessons a teacher could get the students to explore.