Tritonia

Police Operation is a science fiction novella by H. Beam Piper first published in 1948.

Hunting down the beast, under the best of circumstances, was dangerous. But in this little police operation, the conditions required the use of inadequate means! 

Police Operation is a parallel Earth story, a cop from an alternate Earth is trying to fix a screw-up on our world without being too obvious about it.

Police Operation was first published in Astounding Science Fiction, July 1948. 

Henry Beam Piper (1904-1964) was an American science fiction author. He wrote many short stories and several novels. He is best known for his extensive Terro-Human Future History series of stories and a shorter series of "Paratime" alternate history tales. Piper's stories fall into two camps: stark space opera, such as Space Viking, or stories of cultural conflict or misunderstanding, such as Little Fuzzy or the Paratime stories.