I'm writing a story in which the bad guy thinks a certain planetary alignment is just the right time to launch his evil on the universe. The heroes and the bad guy are stuck in a 'cellar' but it has shafts which align just right with this planetary omen. (Rather like the shafts in the Great Pyramid line up with something or Stone henge lines up with the solstice.)
I have no idea about astrology / astronomy so I would like help in choosing the alignment. I'm not bothered what it is, an eclipse, certain planets all in the same sign - as long as the guys could see something through a shaft (altho I could change that if nec) AND whatever the alignment is it is considered evil or sinister.