In Macbeth, Malcolm and Donalbain flee Scotland immediately after their father, King Duncan, is murdered, each going to a different country to protect themselves from being killed next. Malcolm escapes to England, while Donalbain goes to Ireland.
They make this decision because they realize that whoever killed Duncan is still at large and could easily target them next. Rather than trust the other nobles, who might be pretending loyalty, they decide that staying would be too dangerous. Their flight, however, has unintended consequences: because they run away so quickly, it makes them look guilty in the eyes of others, helping Macbeth rise to power.
Malcolm and Donalbain’s decision to flee is an example of how appearances can belie reality. Malcolm and Donalbain act out of fear and self-preservation, but their actions are misinterpreted as treachery, allowing the real criminal to seize the throne.