Betrayal of the bystanders. It is something many of us have experienced. It goes hand in hand with a narcissist's abuse. They make sure they surround themselves with dupes who love a lie.
Which reminds me of what the Bible says in 2 Thessalonians. It talks about those people who have never learned to "love the truth"...the consequences of this are then stated. Because they don't love the truth, they are completely susceptible to delusion. The axiom here is: If you don't love truth you will believe and love lies.
This, to me, is a scary reality. I long ago decided I would embrace truth because the truth is where life resides. Lies may accomplish short term goals, but in the long run living in lies embrace life-destroying effects. The complicit bystanders who lap up gossip like a cat laps cream are exposing their love of lies. They are dangerous to your life. When they are exposed to you as the result of a narcissist's attempt to assassinate your character, your best choice is to put as much distance between the credulous bystanders and your self as possible.
Kathy Krajco has clearly defined the bystanders as she does all topics she addresses. Go have a read. She is condemning the bystanders who actually have personal knowledge and experience of your character. I can hardly imagine that anyone who has stood up to the narcissist in their family has not experienced this "betrayal of the bystanders". Those people who have known you for years, decades, and yet suddenly un-know everything they ever knew about you to believe the complete opposite of what you are. It is a particularly cruel act. One that demands you apply a hatchet to any relationship you had with them. Beware of people who "Drive Under the Influence of a Narcissist" (DUIN). They are as dangerous as the N. They are drunk on lies and not safe for close association.