The correct way to form the comparative of the adverb sadly is more sadly, and the superlative is most sadly.
Although, you can say sadlier and sadliest, but I don't think that is widely accepted in grammar.
A patrol goes into the mountains for a weeklong operation to monitor enemy movement. The jungle is spooky, and the men start hearing strange, eerie noises which become an opera, a glee club, chanting, and so on, but the voices they hear are not human.
im sorry if im wrong :)