YA Fantasy-Thriller Trilogy from the 90s maybe?? A girl and maybe two friends finds a diary in an old house containing a poem about fire and love and circles and three and at the end of the poem "love will conquer all". The poem is all vague but then it all comes true!
Somewhere in the story they go under this big ole tree, and there's a supernatural connection with the past where they solve some mystery/injustice from a hundred years ago or something. I vividly remember them finding the journal, reading the poem, and then going separate ways in a big ole creaky cobwebbed house...there may or may not have been black and white checkered tiles in the kitchen.
Can't remember title, it was in my local library about 15 years ago and I would like to read it again. I was a bit obsessed.