The Dirty Pair Strike Again is the second light novel of the original series written by Haruka Takachiho. It was released in 1985.
Yuri and Kei are sent to the mining planet Chakra, the disgrace of the galaxy, because one of the mining engineers was attacked by an unknown animal. Although he was attacked, the wounds healed in three days. On Chakra, which is complicated by the ulterior motives of its three leaders--the mining owner, the mayor, and the preacher-- unexpected facts appeared to the pair as they start investigating for the truth, together with the handsome sheriff.