Born in 1912 in the third generation of a selective breeding experiment run by the Ira Howard Foundation, Lazarus (birth name Woodrow Wilson Smith) becomes unusually long-lived, living well over two thousand years with the aid of occasional rejuvenation treatments.
He acknowledges that such a long life span should not be expected as a result of a mere three generations of selective breeding, but offers no alternative explanation except by having a character declare: "A mutation, of course — which simply says that we don't know".
[2] In Methuselah's Children, Long mentions visiting Hugo Pinero, the scientist appearing in Heinlein's first published story "Life-Line", who had invented a machine that precisely measured lifespan.
But the pieces fit together rather well, and Heinlein must have had some reason for including the anomalous and cryptic reference to McRae's [sic] recall of events that apparently predate his birth.
Ten percent of them have elected to end "The Masquerade" and live publicly, with the approval of the Howard Foundation, but this process has backfired.
With the aid of the elected head of the world government, Slayton Ford, Lazarus hijacks the New Frontiers, a starship designed to travel to distant stars, and liberates the Howards.
With the ship thus modified, the Howard Families, under the leadership of Lazarus Long, escape the Solar System in search of a planet of their own.
Upon return to Earth, the Howards learn that a rejuvenation treatment has been developed to approximate the secret of longevity supposedly held by them, thus permitting Lazarus, who has grown old, to regain his youth.
This search, using a "Zwicky box", is performed by an artificial intelligence named Minerva, who handles most of the computerized functions of the planetary government, is in love with Ira, and becomes friends with Lazarus.
"[4] Lazarus also appears as a minor character in The Cat Who Walks Through Walls and plays a role in Heinlein's last novel, To Sail Beyond the Sunset, which is the life story of Maureen.