Rules and Restrictions in Pushing Daisies
In the show, Ned the Pie Maker's ability to touch the dead and bring them back to life are governed by three rules.
First Touch, Life. Upon first touching the dead, Ned is able to revive them instantaneously. This is how Ned is able to investigate the murders for Emerson Cod, by bringing the dead back to life and simply asking them who the murderer was. He first learned this trick in the Pie-lette, when he brought his dog Digby back to life.
Second Touch, Death. Once re-animated, a person or other life form will remain alive until Ned touches him, her, or it again – and this time it's dead for good. Unfortunately, Ned learned this rule when his re-animated mother gave him a kiss goodnight.
Compensation. If the re-animated person (or animal) stays alive for 60 seconds then somebody nearby will die in their place. Ned learned this rule by reviving his dead mother, and then killing his neighbor's father. The one minute duration period was discovered by young Ned in The Fun in Funeral, when he tested out the duration period with fireflies.
Rule 4: Accepted Rule
Not Immortal. When Ned brings a dead person back to life, it does not make that person immortal. The reanimated deceased is still liable to injury and even death again, without the "Second Touch" rule. This is explained in the episode Bzzzzzzzz!, after Ned states to Chuck after she's covered in bees, "Just because you're alive again doesn't mean you can't be dead again. There's a reason I don't let Digby play in traffic." And given the intensity of his reaction, it is possible that Ned can't revive a dead person he's already revived.