Wondering if someone can help me – although I think this is a very long shot as my memory is vague:
I used to read this book/series in the 90s. The story involved a gang of kids/teens battling with ”Ooze” or ”slime” of some kind. Also there was an alternative dimension which the children traveled to occasionally, like a mirror version of the town they lived in. It's also possible that they were traveling to the future ? I remember the town was desolate and abandoned in this alternate timeline/dimension.
The only other detail I remember is that the kids traveled to this mirror-town and found a gravestone with another child’s name scratched into it. The name was something ”Poole”. Shane Poole?
that’s literally all I remember haha. If anyone knows what I’m talking about please let me know!