Supergirl: Reign of Tomorrow! Mini-Series Bundle Issues 1-4

It is the first comic series to feature the Post-Crisis Supergirl, sometimes known as Matrix. Matrix first came to prominence as the modern Supergirl in the "Return of Supergirl" storyline running through Superman #21-22 and Adventures of Superman #443-444. This mini-series resolves a year's worth of subplots revolving around Supergirl's relationship with billionaire, Lex Luthor.