Trendy Lee-Mobile was the wife of Uppward Lee-Mobile, and was a willing accomplice in his crimes. She was a slender woman with light hair and full lips.
Trendy and Uppward operated a finance scheme wherein in they embezzled funds from investors. One of their clients Walter Strong attempted to withdraw his funds, and Trendy killed him by injecting a deadly poison into his body using an artificial fingernail. This created the appearance that he had died of a heart attack.
Strong's employer Diet Smith found the idea of Strong having a heart attack to be implausible, since Strong had recently passed a company physical. Smith contacted his friend Dick Tracy, who soon discovered Strong's connection to the Lee-Mobiles.
During the course of Tracy's investigation, Uppward died in an accident. Trendy attempted to use her poison fingernail on Tracy and Sam Catchem. She was unsuccessful, and the attempt linked her to the murder of Strong. She was taken into police custody.