One Last Homecoming

Sherry had planned a quick trip to her home town for her forty-year class reunion, to see the current classes' Homecoming game. Instead, she arrives to find the high school just as she remembers it, complete with long-demolished buildings and long-retired teachers. It's Homecoming, all right -- her senior year. For someone with happy memories, revisiting one's younger days might be pleasant nostalgia.
Sherry dreads the thought of being stranded in the past, forced to reassume the old roles after decades of independence. How can she return to her own time when she has no idea how she got here? Worse, a hostile entity is making its presence known -- and it may not want  to let her go back. And the Homecoming game isn't the one she remembers from four decades ago.