This month's topic challenge is Madeleine L'Engle's Time Quintet. However, although I was a fan of L'Engle's books as a child, I knew nothing of a "Time Quintet" until I was an adult. Rather, when I was in elementary school, circa 1985, I received a boxed set edition of "The Time Trilogy."
Moreover, the Wikipedia page for the series lists (in spite of its "Time Quintet" title) eight books in the series.
A Wrinkle in Time (1962)
The Arm of the Starfish (1965)
Dragons in the Waters (1967)
A Wind in the Door (1973)
A Swiftly Tilting Planet (1978)
A House Like a Lotus (1984)
Many Waters (1986)
An Acceptable Time (1989)
This leads me to my question: What different collections have there been of these books? Lots of other juxtapositions could have been possible over time. The only consistent connection among the books is that the main characters are all members of Meg Murry-O'Keefe's family. In the introduction to A Wind in the Door, L'Engle even specifically says that the book is not a "sequel" to A Wrinkle in Time, since it tells a completely unrelated story.