The book is in a see-through plastic bag to keep it safe until someone finds it. Tucked in to one of the pages there's a note:
This story was a favorite of someone who isn't here anymore. Hopefully whoever finds this can enjoy it too. I only ask one thing, please pay it forward. Do something kind, whatever you like, as big or as small as you like, for 3 people. They can be people you know, people you don't, or, like this, you can do something for no one in particular. Just include a note like this one with whatever you do asking for them to pay it forward too. If you decide not to, no one will know but you, and that's okay. But I hope that with small, easy, acts of kindness we can make our strange home someplace brighter and happier.
The note is typed and unsigned to keep it as anonymous as possible.