Summary: Opportunity to explore hidden aspects of yourself, including thoughts about mortality. Attraction to mysterious subjects. Be cautious during this time, as difficult aspects of Mercury may bring danger or investigation.
This interpretation is for when Transiting Mercury is going through your natal eighth house.
This is a very favorable time to get in touch with the hidden aspects of yourself, since this type of energy is related to a very deep way of thinking, where there may even be a concern for mortality, yours and your loved ones.
This transit can lead to obsessive thoughts related to death. It activates the hidden areas of the mind, where subconscious thoughts throw seeds that then bloom in consciousness, and attracts you to any subject that has hidden tones, for example, life after death, the occult sciences and all kinds of mysterious phenomenon. There is also the possibility of communication with disembodied entities if Mercury is directly connected to Uranus, Neptune and Pluto.
During this transit, sex may be subject to scientific curiosity or intellectual interest. If Mercury makes difficult aspects, be careful, because your secret investigations could put you in danger, or you could be subjected to investigation.