Tandy Bowen, alias Dagger, is among the heroes who joined Captain America's Anti-Registration alongside Cloak. She later joins the others as they head to the Geffen-Meyer chemical plant, only to be trapped by Iron Man, Maria Hill, and S.H.I.E.L.D. in an attempt to end the Civil War quickly, either by negotiation or by catching every unregistered superhero working with Captain America.
Tandy Bowen was born in Shaker Heights, Ohio on February 11th, 1994. She had a privileged upbringing with her mother Melissa being a supermodel and her father a Roxxon engineer. When she seven her father left the family to go to India seeking "spiritual rebirth." Her mother later remarried to her manager Phillip Carlisle. Although kind, Tandy was still hurt by her father's leaving and did not accept Phillip. Her mother also neglected her.
Tandy left home on a bus for New York City. While there, a man tried to rob her but was stopped by the homeless Tyrone Johnson. She bought him food and the two became friends. Dr.Simon Marshall and his men rounded up runaways, offering them food and shelter. Naive, Tandy agreed, and Tyrone went with her, suspecting things were not right. There, they were knocked unconscious and injected with a designer drug the Maggia wished to use as a replacement for heroin. Because of latent mutant genetic factors and some magical interference by D'Spayre, who masqueraded himself as Marshall, Tyrone and Tandy survived while the others died due to the drugs' effects.
They escaped by jumping into the river, and both began manifesting superhuman powers. With this discovery, the two seek help from Dr. Strange who gives Tyrone a cloak to hide his shadow-like appearance and Tandy a necklace and a crescent moon tattoo on her face that helps control her abilities better. They discovered Tandy could keep Tyrone in check. Marshall's men attacked but were consumed by Cloak's hunger then hit with Dagger's light daggers. The two became Cloak and Dagger, pledging to protect other young people from the dangers they had encountered and Tandy became fiercely loyal to Cloak and fell in love with him.
Marvel: Ultimate Alliance 2: Story
Dagger joined the Anti-Registration Campaign alongside her partner Cloak. They were teleported by Cloak to the Geffer-Meyer power plant, where Cloak was shot by a S.H.I.E.L.D sniper. Cloak's injured body was protected by Dagger and the White Star units.