The Kitten Sisters were originally performers who specialized in tumbling and acrobatics. When their show was no longer successful, they turned to crime. They stole jewels which they would sell to a fence. A skier named Inga Yelma, one of their former associates, learned of their criminal activities and planned to expose them. The Kitten Sisters drew straws to see who would eliminate this threat, and the one who drew the short straw (Fifi) killed Inga with an arrow while Inga was performing a ski jump.
The high-profile nature of the murder attracted Dick Tracy's attention. He investigated, but the Kitten Sisters were able to overpower him and left him for dead. They stole his 2-Way Wrist Radio, which they attempted to sell. Their fence did not want the radio, so they kept it.
The Kitten Sisters were found and became fugitives. They joined the traveling show of Spike Dyke, who eventually discovered their identities. Spike was an old friend of Dick Tracy, and he informed Tracy of the Kitten Sisters' whereabouts. After a brief escape attempt, the Kitten Sisters were captured and Fifi's identity as the one who had murdered Inga was established.