On Just Publishing Advice:
The past perfect tense is very useful in writing. We use it to show that an action occurred before another action in the past.
It is a tense that concisely creates order without using time clause expressions like, and then or afterward.
Although it is a perfect tense because it uses the auxiliary, had, it has no relationship at all with the present perfect tense.
The best feature of past perfect, which is sometimes called pluperfect, is that it is super easy to use for any writer.