Tandy Bowen was a sixteen-year-old who was neglected by her mother and felt distanced from her new stepfather. She ran away from home and came to New York City. Once she was in New York she met Tyrone Johnson, a fellow runaway. Johnson had planned to steal her purse, but when he saw another thief beat him to it, he tackled the thief and returned Tandy's purse to her. This began their long partnership as the two came to rely on each other to get along on their own. Tandy and Tyrone were offered shelter by henchmen of Maggia crime lord Simon Marshall. Marshall"s hospitality was only a front for testing a new synthetic narcotic. The two teenagers escaped, but not before they were injected with Marshall"s drug, which awakened latent mutant abilities in both of them (a process secretly encouraged by the demon D'spayre who had hoped to feed upon their angst). Tyrone found himself compelled to drain the life-force of others by enveloping them in the darkness of his cloak. Tandy, on the other hand, gained the ability to project light in the form of energy daggers, which she used to subdue Tyrone's darkness. The two decided use their powers to protect the streets from men like Marshall, and became known as Cloak and Dagger.

The two vigilantes have specialized in combating drug-dealers and helping runaway children. For all the work that Cloak and Dagger have done to help reform addicts and topple dealers, they realize that drug abuse is an evil greater than they can ever hope to conquer. The duo have often teamed with Spider-Man. Unlike Cloak, Dagger enjoys adventuring and has often run into trouble without him. She has even served as a member of the New Warriors and as a part of Daredevil's Unnamed Super-Hero Team. Because of Cloak's anti-social behavior, Dagger has often been his only link to humanity. Dagger has protected Cloak from being manipulated by various enemies including the Darkling, Nightmare, and Mister Jip. A short time ago Cloak and Dagger were manipulated by the Pride into tracking down their six runaway children. The heroes found the Runaways and learned the truth about the Pride. Promising to help the children, the Pride found them instead and wiped their memories of the whole event.

Recently Dagger was attacked and kidnapped by a 'stalker' who managed to copy Cloak's powers causing all of their hero allies to believe that Cloak had attacked Dagger. Cloak sought out the assistance of the Runaways who helped Cloak rescue Dagger and fight off her stalker.