Princess Lightning (電撃王女, Dengeki Oujo) is the fourth chapter in Princess Resurrection manga series.
Hiro runs out of blood and collapses in the street. Having been mistaken for dead, he is taken to the Sasanaki City Hospital. Sawawa takes care of the mansion's bills and remarks that they are using an unusually large amount of electricity for one house, to which Hime responds it's needed to charge Flandre's battery. Hime gets the feeling that she's forgetting something, but can't remember what.
A nurse informs the hospital director, Housei Sangaida, that the "dead man walking" has arrived once again. After Hiro awoke in the morgue and disappeared a month prior, his interest is piqued, and he confronts Hiro with his staff. The staff chase Hiro throughout the hospital, attempting to gain his knowledge of "the secret of resurrection." Hiro makes it to the first floor only to find that all of the doors and windows have shutters.
After her dinner, Hime finally remembers what she had forgotten--that Hiro would be running out of blood by then. She takes Flandre and heads for the hospital, noticing the heavy concentration of bats in the sky that night.
Cornered, Hiro is stabbed by one of the hospital patients--who don't seem entirely human. The director once again tries to find out his secret, but is distracted by Hime's arrival and heads out to ambush her. Hiro senses Hime is in danger and jumps out of the window, landing on a truck in the parking lot in front of her and Flandre. He, once again, wakes up in a hospital bed. Hime tells him that she has given him blood, and the three are alerted to banging at the door. The director and his staff are attempting to break in.
Hime defeats several of the staff members with a defibrillator; it is hooked up to Flandre's battery, giving it lethal power. Upon the staff members' collapse, Hime notices bite marks in their necks, realizing they were the puppets of a vampire, the director included. Furious that the director attempted to harm Hiro, she electrocutes him and leaves his burned corpse in the hallway, lamenting that his master never came for him. Hiro realizes that Hime came to the hospital solely to save him, and did not initially seek out the vampire threat.