S03E11: 'Mystery Spot'

Sam and Dean investigate the disappearance of a man who went missing at a tourist location.

While searching the site, Dean is shot and killed by the owner. Sam is devastated but stunned when he wakes up the next morning to find Dean alive and well.

As the day unfolds, Sam realises he is reliving the previous day and tries to prevent Dean's death, but to no avail. Dean dies again and Sam must learn to live life without his brother by his side.