YA book about summer in a magical home with a hidden turret /s

[Israel]

I read this fiction book in the late 1980s, as an upper grade school student (5th or 6th grade). It had the word "Summer" in the title, I think. It was probably about 200 pages long.

It was about siblings who lived in some relative's house for the summer. One of the siblings was a lonely boy. While exploring the large house, he found a bookshelf that was a hidden door leading to a staircase and a turret. Entering the turret, he found other strange people whom he befriended.

I don't remember the rest of the plot, except that it involved betrayal by those strange people, whom the boy eventually rejected. This rejection caused the turret to disappear and the hidden passageway to become only a hidden closet.

One more thing: The chapters were numbered in binary, with the numbers engraved on cubical stones, and this was significant to the story somehow.

Thanks for your help!

[Michele]

Do you recall when the book was set, or where? For example, 1950s Oklahoma or 1970s England? Do you have any recollection of why the kids were staying at this house? How old were the kids in the story? When you say "strange people" can you say anything more about why or how they were "strange" ?

[Israel]

My memory is really fuzzy, so I'm not sure how accurate the following details are.

I don't remember where the book was set. If I recall, the time and the place were not material to the plot. The time was probably modern, contemporary time.

I think the kids were spending the summer there with distant relatives who lived there. Maybe their parents were vacationing elsewhere.

The kids were pre-teen to teenage.

The people that the boy discovered were strange in that they seemed to be able to enter the normal world and not be noticed, like ghosts. But in other respects, they were normal people to the boy.

The boy also visited a mysterious elderly man down the street who gave him a new cube (with the next binary number on it) each time he visited.

Weird, huh? Or maybe my memory is weird.

[Israel]

Well hm, that wasn't too hard. A few more Google searches turned up the book I was looking for:

A Really Weird Summer
by Eloise Jarvis McGraw

https://www.goodreads.com/book/show/1...

[Michele]

A Really Weird Summer for the GR click.