Marcus Rebbeck Lear was the son of Goneril and Augustus Lear and the brother to Trajan and Averill Lear. He was ten years old when Pegasus departed on its journey of exploration, accompanying his mother, who was Pathfinder Three’s Executive Officers.

Darker, more aggressive and more athletic than his brother Trajan, Marcus liked Chocolate-mint-coffee-and-cream, but disliked Sapphireans, finding them undisciplined and shallow.

In Book 03: Bodicea , Goneril Lear used Marcus Lear as a political prop in an attempt to gain favor with the Bodicean Matriarchy.

In Book 04 Winter , Marcus Lear played Calvinball and went Hull Surfing with Matt Driver and his brother Trajan.

In Book 06: Crucible , Marcus accompanied his mother and father when they left Pegasus to serve on Pathfinder Six Lexington Keeler.

Marcus Lear died in a shuttle crash on the planet Nocturne while transporting his father to a wedding and diplomatic reception. It was widely believed that the shuttle was sabotaged, possibly by cyborgs from the planet Ecco 1.