In the Dark of the Night book by John Saul

The rambling lakeside house called Pinecrest has lain empty since its last owner went missing seven years ago. But for the Brewster family it will be this year's holiday retreat, and for the kids Eric and Marci it's the perfect place to spend a lazy summer exploring.

Which is how Eric and his teenage friends discover a curious collection of discarded objects stowed in a hidden room in the carriage house. The bladeless hacksaws, shade-less lamps, tables with missing legs, a headless axe handle - these unremarkable items add up to a pile of junk. Yet someone once took the trouble to list each worthless relic in a cryptic ledger, thus provoking a great mystery that is now whispering, coaxing, demanding to be solved. The more the boys devote themselves to piecing together the puzzle, the more their fascination deepens into obsession. Soon their days are consumed with this weird collection, while their nights become plagued by ever more ghastly nightmares.

And finally when a horrifying discovery surfaces, so does the chilling truth about a twisted legacy with a malevolent life of its own.