Aha! This is a definite clue. Some sort of security wizardry has been applied to this table, so that when I query it, a bunch of junk gets tacked onto my query.
I have no shame in admitting that I couldn’t remember at all what feature this was and how it works. A lot of security features were added in SQL Server 2016, and the whole point of a sample database like this to kick the tires of the features.
Kendra’s post frames it as an impostor syndrome check, whereas I read it as a murder mystery.