[2] The book covers several periods from the life of Lazarus Long (born Woodrow Wilson Smith), an early beneficiary of a breeding experiment designed to increase mankind's natural lifespan.

This story concerns a 20th-century United States Navy seaman, midshipman, and officer David Lamb, who receives multiple promotions while minimizing any semblance of real work or combat by applying himself enthusiastically to the principle of "constructive laziness".

Lazarus tells of his visit as an interplanetary cargo trader to a planet, where he bought a pair of slaves, brother and sister, and immediately manumitted them.

However, having confirmed that there is no risk of genetic disease in their offspring (described as the only valid argument against incest), Lazarus solemnizes their marriage and later establishes them as the owners and operators of a thriving business.

At the end of the story, he reveals that the twins looked the same age decades later and expresses his belief that they were his own descendants, from an earlier time that he had been a slave on the same planet.

Lazarus, now working as a banker and shopkeeper on the frontier planet and keeping his true age secret, saves a young girl, Dora, from a burning house and becomes her guardian.

When she becomes an adult, he leaves the area but returns as a younger man and marries her, and the two move away to start a new settlement, where Lazarus' long life is less likely to be noticed.

[nb 1] In the trenches of the Western Front in France, he is mortally wounded, but is rescued at the last moment by his future companions from the framing story and returned to his own time.

One of the suggestions is to have his memory and consciousness transplanted into a female clone of himself, at which point Lazarus briefly remembers hearing of the events that occurred in I Will Fear No Evil.

From Methuselah's Children, Lazarus offers to recount the fate of the Jockaira, but another character cuts him off, saying: "Since that lie is already in his memoirs in four conflicting versions, why should we be burdened with a fifth?"