It is a dusty rune. That should have been their first clue that it was dangerous.
In a certain nation, no-one except the Emperor is allowed to have a name. Therefore, the people give themselves pseudo-names called "callings". Examples of callings: A family is known as the Red Sparrow family. The father is called Swooping Red Sparrow. The wife is Bright Red Sparrow Blue Lizard because she was called Bright Blue Lizard before marriage. Their daughter, until she becomes an adult, is Daughter of Red Sparrow. Their sons are Eldest Son of Red Sparrow and Younger Son of Red Sparrow.