The 8th house represents sex and your relationship to the resources of others. It represents death and inheritance. Also, transformational release and your ability to "rebound" from hardships.
It is quite strange that intimacy falls into the 8th house, but so does death. Then again, complicated, deep and secretive Scorpio rules over the 8th house, welcoming the dark with the light. Anything magical and mystical is also represented here -- but secrets and ulterior motives, too.
Your birth chart is divided into 12 "houses" which govern specific areas of your life. At the time of your birth, each planet was located in a particular astrological sign and in one of the 12 houses.