You probably can't see this very well, even if you click to enlarge. I'll try to get a better photo later.
What is it? It's a small patch in the middle of the basement floor that has not been whitewashed like everything else. Why? Because scratched out in the middle of it are the words: "Hi Lois, June 30th, 1945"
I wonder what other clues are hidden around?
When my mom left the house I grew up in, after 35 years, she she wrote our names and "We loved this house" with permanent marker on top of one of the basement beams.