Marco was in charge of all mining processes on El Cavador including equipment. At one point, the mechanic Victor Delgado made a stabilizer for the mining drills so that the ship would experience less shift when the drill went through an ice pocket in an asteroid. Marco had to supervise the installation to ensure the safety of the mining equipment, but was impressed with Victor's work.
Two weeks later, Marco went outside of the ship at night to help Segundo Delgado and Victor prepare the ship's defenses in preparation of an attack from an incoming alien ship. Late in the night El Cavador was attacked by the Makarhu, a Juke Limited ship captained by Lem Jukes, in order to take possession of the asteroid they were mining. During the attack, Marco was struck violently, and taken into the ship by Victor and Segundo. By the time Isabella had arrived, she pronounced that he was dead immediately after being hit by the ship.
Marco's body was released into space during his funeral.