Tyrone "Ty" Johnson (Cloak) and Tandy Bowen (Dagger) meet in New York City as runaways. Tyrone is the son of Otis and Adina Johnson and Tandy is the daughter of Melissa Bowen. Tyrone is a 17-year-old boy from Boston, Massachusetts with a debilitating stutter and ran away to New York City when his speech impediment prevented him from stopping his friend from being shot by the police, who mistakenly believed he had just robbed a store. Tandy is a 16-year-old girl from a privileged upbringing (born in Shaker Heights, Ohio) who ran away because her multi-millionaire supermodel mother was too busy with her career and social life to spend time with her daughter. When they meet, Tyrone considers stealing Tandy's purse, but before he can, a thief steals it and Tyrone retrieves it for her. Afterwards, they have dinner and quickly become friends. When naïve Tandy accepts an offer of shelter from some strange men, wary Tyrone goes along to protect her. The two teens are soon forcibly delivered to criminal chemist Simon Marshall developing a new synthetic heroin for Silvermane and the Maggia, testing it on runaway teens with fatal results. Johnson and Bowen somehow survive injections of the drug, and they flee. During their escape, the drug turns them into superpowered beings.[13] Tyrone finds himself engulfed in darkness and seized by a strange hunger that eases in the presence of Tandy glowing with a brilliant light. Trying to hide his newly shadowy appearance in a makeshift cloak, Tyrone absorbs Marshall's thugs into his darkness while Tandy strikes them down with daggers of light. The two teens dub themselves "Cloak & Dagger", declaring war on drug crime and helping runaway children.[14] They are aided by local priest Father Delgado and Detective Brigid O'Reilly.[15]

Tandy has the ability to create a multitude of light daggers which travel wherever she wills them, and which drain living beings of vitality when struck. Her light daggers also have the capacity to cure certain persons of drug addictions, and can alleviate Cloak's hunger for light (which simultaneously allows her to avoid becoming overcharged). She can even mentally see the hopes of certain people by touching them.