Lars' parents died from spore blight when he was sixteen. After burning the infected old farm he and his sister started and managed a new farm and automated mines. The harsh conditions of the world made him an eligible bachelor at just fifteen but he evaded marriage requests into his eighteenth year.
At eighteen he and Octavia discovered a strange relic inside a mountain. It had been uncovered during one of the planet's frequent violent storms. The pair investigated. Once inside Lars touched a crystal nodule protruding from the crystalline walls and was absorbed by the artifact. Even as Octavia fled the artifact awoke and emitted a great psionic signal into space, bringing together the forces that would fight the Battle of Bhekar Ro.
When the battle concluded the artifact "hatched" into an energy creature. The metamorphosis was achieved by absorbing protoss and zerg, in addition to the energy from a nuclear detonation, but it had no use for the terrans it had absorbed. Before leaving the absorbed terrans, Lars included, were reconstituted unharmed on the planet surface.