Death, personified in the form of Mr. Brink, hitches a ride with Dr. James Northrup and his wife, causing their tragic death in a car accident. This leaves their young son Pud in the care of his beloved grandfather, Julian Northrup, and his grandmother Nellie. Pud's maternal aunt, Demetria Riffle, a sanctimonious, greedy old maid, pretends to be fond of the boy, but really cares nothing for him and only wants his $50,000 inheritance. Gramps, who calls Demetria a "pismire," knows her true nature. Nellie too is aware of her niece Demetria's tendencies, but after Mr. Brink visits the ailing Nellie, Demetria plots to get Pud away from Gramps. When Mr. Brink visits Gramps, Gramps resists, luring him into his apple tree, and refusing to give him permission to leave. Mr. Brink is unable to come down from the tree, because only Gramps has the power to release him, the result of a wish he made after doing a good deed. After the beloved family dog dies upon touching the tree, Gramps orders a fence built round the tree to protect others and Demetria tries to have Gramps's lawyer, Ben Pilbeam, and Dr. Evans declare him insane. Soon, however, Dr. Evans suspects that there is truth to Gramps's insistence that Death is trapped in his apple tree when several cases of certain death do not occur. Evans conducts experiments to disprove Gramps's story, but nothing dies, except a mouse that touches the apple tree. Evans begs Gramps to let Brink down, and appeals to his humanity. He tells him that a world without death will mean added suffering for those with incurable diseases, the old and infirm. Gramps wrestles with his conscience and thinks of his own old age and the burden that he will be to Pud, but cannot let Brink down. The next day, Evans comes with papers to commit Gramps and turn Pud over to Demetria, thus convincing Gramps to let Brink out of the tree. After he gently tells Pud of his decision to go with Brink, Pud cries that he loves his Gramps so much that he wants to go with Mr. Brink, too. Heartbroken when Gramps tells him he can't come too, Pud runs off. Just before Gramps goes to the sanitarium, he pretends that Mr. Brink has said that Demetria and the sheriff are due to die soon. Marcia Giles, Gramps's loyal housekeeper, also pretends to hear Mr. Brinks's pronouncements, frightening Demetria and the sheriff into leaving. While Marcia and Gramps go looking for Pud, who has been hiding, Pud is goaded into climbing a fence built around a tree when Mr. Brink calls him a "baby calf." Pud does not touch the tree, but instead falls to the ground and is paralyzed. Realizing that Pud's terrible pain will only end with death, Gramps takes the boy in his arms and summons Mr. Brink from the tree. Now touched by Death, Gramps and Pud both feel wonderful and walk hand-in-hand beside Mr. Brink, joyful they will be together for eternity, reunited with Nellie.