Just for a Minute Forget About What's Coming Tomorrow

It's been 9 years since Kate met Dr. House. They've gotten married and had 4 kids together. Simply put, their life is perfect. But one day, and unexpected guest arrives in Dr. House's office. Who she is made quite clear, but her intentions aren't? Why did she randomly show up? Will she ruin the perfect life Kate and Dr. House managed to put together after all these years?