Three Days to Never (Tim Powers)

This intricate time travel story deals starts with an old woman dying in the mountains miles from where she was moments ago. It turns out that she had links with Charlie Chaplin and Albert Einstein, and these links bring her to the attention of Mossad, the Israeli security agency, as well as a rival group of spies. The woman's son and granddaughter wind up under attack from both groups because they found some mysterious artifacts in the old woman's shed, including a videocassette of Pee-wee's Big Adventure that turns out to be something else entirely. The story is complex and at many times confusing, but I really cared about the central characters and I loved how it expanded my mind.