Between Heaven and Earth follows one of seven cousins on an individual quest assigned by their late grandfather.
Seventeen-year-old DJ, whose full name is David Junior, sits in a lawyer's office with his family following the death of his grandfather, David McLean. His mother, twin brother Steve, aunts, uncles, and cousins have gathered to hear the will. DJ's father died when DJ was very young, and since then DJ has taken on a protective role, looking after his mother, his brother, and his cousins. His grandfather, who died peacefully in his sleep at ninety-two, was a former World War II pilot, relentlessly friendly and full of life.
The lawyer, John Devine, reads the will and then announces that a substantial sum has been set aside for seven "undertakings," each assigned to a specific grandson. He asks the adults to leave, and the grandsons watch a recorded video in which their grandfather expresses his love, acknowledges that being present for their lives prevented him from fulfilling his own dreams, and explains that envelopes containing individual tasks await each of them. Mr. Devine then reveals there are seven envelopes, not six: Grandpa had a previously unknown daughter, now deceased, whose son Rennie is a seventh grandson.
At home, DJ opens his envelope. Inside he finds Grandpa's signature black beret and three smaller envelopes marked "1, Read Now," "2, Bottom," and "3, End." In the first letter, Grandpa reflects on DJ's nature as a responsible "old soul" and urges him to accept help from others. He then reveals his task: He wants DJ to travel to Tanzania, climb Mount Kilimanjaro, and scatter some of his ashes, stored inside his walking cane, from the summit. Africa, Grandpa writes, is where his "life began again" after the war. A postscript mentions that a man named Elijah will meet DJ at the airport. DJ assumes the climb will take only a few days.
DJ departs carrying the cane, privately scared and harboring a secret fear of flying. After three progressively smaller flights, he lands at the small airstrip in Moshi, a town near Kilimanjaro. At customs, the officer interrogates him about his brief planned stay and his lack of information about his contact. When the cane slips from DJ's hand, the officer examines it, discovers the hidden ashes, and suspects drug smuggling. Armed guards seize DJ and lock him in a cell.
DJ is rescued by Elijah, who turns out to be a justice of the Supreme Court of Tanzania and Grandpa's old friend. Elijah uses his authority to dismiss the matter and shares stories about Grandpa's time in Africa during the colonial era, including how Grandpa treated everyone with respect and anonymously funded Elijah's education. Elijah reveals that Grandpa attempted to climb Kilimanjaro but never reached the summit. Unable to accompany DJ further, Elijah explains that his son, also named Elijah, runs a tour company and will guide the trek.
On the way to the tour office, street children steal DJ's backpack, duffel bag, and the cane while he stops to help a small boy. DJ recovers only the cane, which the thief discarded. An old local man who climbed the mountain hundreds of times as a porter and guide leads DJ to the office, warning him to respect the mountain and emphasizing
polepole, Swahili for "slowly."
At East Africa Walking Tours, DJ meets Sarah, the fourteen-year-old granddaughter of Judge Elijah. She ventures into a dangerous slum to recover DJ's stolen gear, and DJ buys back his belongings. In exchange, Sarah extracts a promise: DJ must insist to her father that she serve as a porter, giving her a chance to become the first female porter ever to climb the mountain. DJ agrees, only to learn that Sarah has never climbed it before.
At a pre-climb briefing, DJ meets Doris, a sixty-seven-year-old British woman climbing to honor her late husband Samuel's unfulfilled dream of summiting Kilimanjaro. Three Finnish climbers round out the party. The guide, Elijah Odogo, Sarah's father, warns about mountain sickness and explains the climb will take five to seven days. DJ, who planned on two or three, is stunned.
Before setting out, DJ opens the second letter. Grandpa confesses he never reached the summit and urges DJ not to let the weight of the request be too heavy, advising him to remember that "life is a journey and not a destination." The climb begins through dense rainforest. The porters refuse to speak to DJ because he brought a female porter onto the mountain, and they give Sarah the heaviest load as the newest porter. DJ and Doris form an unlikely partnership on the trail, and she pledges to help him reach the top.
Over the following days, the group ascends through changing climate zones. DJ's symptoms worsen: persistent headaches, stomach troubles, loss of appetite, and labored breathing. He recognizes these as signs of mountain sickness but refuses to admit it. On the fourth day, they scale the Barranco Wall, a 240-meter cliff face. By evening, DJ acknowledges privately that he may not reach the top.
That night, all three Finnish climbers develop severe mountain sickness. Mr. Odogo takes all porters to evacuate them, canceling the summit attempt. DJ initially feels relief at having an honorable excuse not to climb. He texts Steve, confessing he cannot complete the task. Steve, on his own quest in Spain, responds with encouragement, invoking their grandfather's wartime courage: "I believe in you. Grandfather's waiting at the top." Moved by his brother's faith, DJ announces he is going to climb. Doris volunteers, and Sarah insists she must come too.
The three begin the summit climb at midnight, joining a stream of headlamp-lit climbers on the final route. They battle extreme cold, exhaustion, and altitude, climbing in short intervals. About one-third of the way up, Doris collapses. DJ gives her water and refuses to leave her behind. Later, DJ himself falls and cannot stand. Sarah carries his pack alongside her own, and Doris tells him accepting help is a sign of strength. Near the summit, DJ asks for his pack back so he can carry Grandpa the rest of the way.
They reach Uhuru Peak, the highest point in Africa. DJ stands holding the cane. Doris addresses Grandpa as a man she never knew but whose quality she can see in his grandson. DJ unscrews the cane, pours the ashes into his palm, and says, "Thanks for taking me along on this trip." He tosses the ashes into the wind, which lifts them in an iridescent white cloud until they vanish somewhere between heaven and earth.
Back at base camp, Mr. Odogo surprises them with congratulations, saying he is "too proud to be angry." He punishes them nonetheless with an extended march further down the mountain.
At the hotel in Moshi, DJ opens the final envelope. Grandpa writes that it does not matter whether DJ reached the summit; what matters is what is inside of him. He hopes DJ has learned to go
polepole and to accept that failure does not make a person a failure but merely human. He invokes the belief of the Chagga, an Indigenous people of the Kilimanjaro region, that a man never dies as long as he has children, affirming he lives on through his family. He asks DJ to someday pass the beret to a future descendant named David, adding, "And don't make him climb any damn mountains!" DJ places the beret on his head, looks in the mirror, and sees his grandfather looking back at him. They are both smiling.