I enjoyed this story, don't get me wrong, but it does have one plot point that is so absurd I have to comment.

According to records, 20 people have gone missing over the course of a decade. But that's an error because the column isn't summing properly.

Actually, people have been disappearing at a rate of one every two hours for a decade now. That's over 175,000 people.

Seriously, there are people in charge complicit in hiding the real number, but they have no idea the number is so big. Are we supposed to believe so many people have gone missing and nobody has raised concerns about how many of their friends and loved ones have gone?

175K workers have vanished and the people making the work rotas haven't noticed so many people not showing up?

While it's a cute idea, it relies entirely on treating people strictly as numbers and ignoring the fact that other people would notice the disappearances and act on their concerns.