In the midst of her midlife crisis, Amelia gets hit by a bus on her 40th birthday. When she wakes up she suddenly finds the year is 2002 and she's 18 again - allowing her to right all the mistakes she made the first time round. But as she finds herself stuck in a "Groundhog Day" time loop - waking up every morning on her 18th birthday - she realizes there's something else going on that will need to be fixed before she can leave the past behind forever.
On her 40th birthday, Amelia makes a fateful wish to be 18 again back in 2002 but soon regrets it when she's stuck reliving the day over and over again.