The person who called herself Endless Mahoney was a shapely blonde woman who claimed to be a sister of Breathless Mahoney (whom she resembled).
Endless and her associate Minty attended the surprise birthday party of Chief Brandon. They were confronted by Dick Tracy as they left.
Endless stated that she was married to Raymond Czar, a nightclub owner and suspected gunrunner. Czar had gone missing and Endless expressed her belief that he had been targeted by the hired killer known as Mr. Mirror. She asked for Dick Tracy's help, then departed.