Marcus is portrayed by BJ Tanner.
Marcus was born sometime around the year 2409 to Doctor Claire Finn, an experienced medical officer in the Planetary Union. Marcus has no father. Claire desired children, but by her own description, she never found a man suited to be her husband. Marcus was born through artificial impregnation of his mother. Several years later, his brother Ty was born by the same method.
Aboard the Orville Edit
Claire requested a transfer to the Orville in the year 2419, and Marcus and Ty followed her, living on the ship as civilian passengers. Marcus attends school on board the ship. In his free time, he enjoys playing Space Dragons in the Environmental Simulator.
Shuttle crash Edit
In the winter of 2420, Claire wants to spend more time with her sons, so she plans a vacation to Arboreus Prime. Marcus is non-plussed, he would rather attend a medieval battle camp in the Environmental Simulator, and calls Arboreus a "stupid play planet." The trio leaves in a shuttle piloted by Science Officer Isaac.
Marcus wants to play games on an unidentified, hand-held device while they travel to Arboreus. When Claire forces him to turn it off, he tells his mother that she 'sucks,' and, minutes later, turns the game back on.
Ty is annoyed that Marcus disobeyed their mother. When Marcus drops the device during mid-flight turbulence due to a gravity shear, Ty recovers and throws it, hitting the shuttle's navigational console. The shuttle is thrown off-course and sucked into the gravity well of a nearby spatial fold.
The shuttle emerges from the fold badly damaged and in uncharted space. To survive, Isaac intentionally crashes them onto the surface of the nearest inhabitable moon, but the shuttle splits in two and Claire is separated from the others.
Isaac decides to leave the boys in search of Claire. Before he goes, he introduces Marcus to the PM-44, a basic energy weapon, for protection. Isaac's decision would risk their lives. That night, a cannibalistic inhabitant of the moon preys on the children from the dark of the forest. The man grabs Ty and attempts to abscond, and Marcus is either too afraid or too unfamiliar with the energy gun to shoot him. Fortunately, from elsewhere in the woods, Isaac momentarily stuns the man with the PM-44. The kidnapper flees.
Isaac could not find Claire on foot, but he believes that re-powering the shuttle with dysonium would allow them to conduct a wider search and to send a distress message to the Orville. Marcus recalls that some satellites of the galaxy host deposits of dysonium. A brief search with Isaac's comscanner reveals possible surface veins of the energy source several kilometers away. Isaac congratulates Marcus for his simple, yet intelligent idea.
The three set off for the source of dysonium. They are waylayed by a group of starving cannibals who demand the children, but Isaac is able to fend them off. The trio finds enough dysonium to restore power to the shuttle, and they begin their return. Meanwhile, the Orville began a search for them. The crew finds the correct gas giant, but with 36 habitable moons, they must search one at a time.
The next morning, Ty shows symptoms of a serious illness. Unbeknownst to them, the child is sick with poloxus poisoning from exposure to contaminated water. Claire messages Isaac from her comscanner and receives their coordinates. She was taken by an inhabitant named Drogen shortly after the crash and held captive; she kills Drogen and leaves. Along the way, she is followed by a throng of cannibals.
When Claire reaches the three at the shuttle, Isaac sends a brief distress signal. However, the cannibals attack the four. Isaac, Claire, and Marcus use their energy weapons to repeal the attack. Claire instructs her son to set the gun to stun. "They may not value life, but we do." Isaac encourages Marcus to shoot calmly. Just then, the Orville arrives: it received the distress communication, and the cannibals flee.
Like many siblings, Marcus fights frequently with his brother and his mother. For examples, Marcus kicks Ty's seat on a shuttle when Ty farts - probably in an effort to annoy Marcus, and Marcus willfully disobeys his mother by playing his gaming device on the shuttle. Yet the shuttle crash of early 2420 was an important moment of maturation for Marcus. Marcus realizes he loves his brother and his mom when Ty falls ill from poloxus, and Claire goes missing. He encourages Isaac to hold Ty's hand and to tell him a bedtime story, and tearfully apologizes to his mother for saying she 'sucks.' After nearly losing both, Marcus fights less with Ty and Claire. Further, Marcus and Ty begin to adore Isaac, and see him as a fatherly figure in their lives.
- Marcus has a friend named Bradley, a boy with alcoholic parents who permit him to attend medieval battle camp in an Environmental Simulator.
- Marcus and Ty are locked out of their quarters when Claire copulates with Lieutenant Yaphit. They complain to Chief of Security Alara Kitan.
- Around April, 2420, Marcus and Ty offer to help Isaac scan the Orville after a spatial anomaly damages part of the ship. Isaac initially rejects their help but, after Navigator John LaMarr criticizes him, relents.
- Marcus notices that plants in one section of the ship have died. The discovery leads the special Science and Engineering task force to believe that the section of the ship entered two-dimensional space.
- ↑ On the basis of Marcus's perceived age and the starting year of the show, 2418.
- ↑ 2.0 2.1 2.2 2.3 Episode 8: Into the Fold
- ↑ Episode 1: Old Wounds
- ↑ Marcus tells Isaac that he learned about Dysonium deposits on other planets in class. Episode 8: Into the Fold
- ↑ 5.0 5.1 5.2 Episode 11: New Dimensions
- ↑ Episode 9: Cupid's Dagger