When he finally arrived in Tonga, his first assignment was on the remote island of Niuatoputapu, which had had only limited contact with the outside world in the form of an occasional telegraph and a visiting boat.

[1] After a year on Niuatoputapu, Groberg was assigned to more developed islands and served as a district president supervising smaller branch congregations of the church.

He had little contact with his supervising mission president and nearly drowned when pushed out of a boat during a major storm; he also suffered from exhaustion frequently.

Groberg was denied an extension to his mission that would have allowed him to accompany a group of church converts to the New Zealand Temple.

Groberg wrote a book about his mission from his memoirs called In the Eye of the Storm, which was adapted into the 2001 Disney film The Other Side of Heaven.

[2] The New York Times explains of Groberg's character, "The narrator and hero of The Other Side of Heaven, is a Mormon missionary dispatched to the Tongan islands in the Pacific Ocean immediately after his high school graduation in the 1950s.

"[3] A sequel to the film, The Other Side of Heaven 2: Fire of Faith, was made in 2018 with the same actor, Christopher Gorham, in the role of Groberg.