Plot
A bizarre delivery to Supergirl's apartment quickly has her hopping dimensions and traveling through deep space as she fights alongside Superman and the Green Lantern Corps. Shortly after Kara first meets the man who will become one of her worst enemies, Reactron! In the aftermath of that battle, Supergirl swears to save the life of a child dying from cancer. Unfortunately, she is about to learn a very bitter lesson about her own limits.
Action Comics #850 (Superman: Family)
Supergirl (Volume 5) #23 (Tesseract)
Supergirl (Volume 5) #24 (Star Child)
Supergirl (Volume 5) #25 (Boom)
Supergirl (Volume 5) #26 (Breakpoint)
Supergirl (Volume 5) #27 (The Girl of Tomorrow)
Supergirl (Volume 5) #28 (Way of the World (Part I of III))
Supergirl (Volume 5) #29 (Way of the World (Part II of III))
Supergirl (Volume 5) #30 (Acceptance)
Supergirl (Volume 5) #31 (Way of the World (Part III of III))
Supergirl (Volume 5) #32 (Time Heals All Wounds)
Supergirl (Volume 5) #33 (Aftermath)