In 2517, he was kidnapped from his home and taken to Reach. He was then conscripted into the SPARTAN-II Program. Even though he was only six years old, he learned to fly a Pelican dropship just by watching the pilot fly him into camp. He stole one, and flew it alone, subsequently blowing it up when the UNSC pursued him. Afterward, he met Adriana-111 and Jai-006 to form Gray Team.
In 2525, along with the rest of the SPARTANs, Mike underwent augmentations to enhance his physical and mental capabilities. He made it through the process as one of the 33 out of 75 SPARTAN-IIs to survive.
Battle of the Rubble
- Main article: Battle of the Rubble
- “At least we're both making friends out here. Shame Jai lacks the social knack...”— Mike after forming a plan with Juliana
During the Human-Covenant war, Mike and the rest of Gray Team were sent deep behind enemy lines to wreck havoc on both the Covenant and Insurrectionists. Mike flew Gray Team's Prowler, the Petya. When they discovered the Rubble, Mike believed that if the Rubble turned out to be a threat, they should destroy it with their complement of Shiva-class Nuclear Missiles. Shortly afterward, the AI, Juliana made her presence known.
When the UNSC Midsummer Night arrived in the system, it was under attack by multiple Insurrectionists. He correctly came to the conclusion that he could not save the Midsummer Night from all the ships, but shortly afterward Juliana informed Gray Team that she could. She sent the coordinates of Ignatio Delgado's location to Mike, and ordered them to keep Delgado protected and she would help free the Midsummer Night crew. Mike knew that the Kestrel was in-system, though, and Gray Team first overtook the Kestrel, using an EMP bomb that Mike designed.
Mike continued piloting the Petya, following the Distancia. He survived the Battle of the Rubble and Battle of Metisette, and later, when being debriefed at Falaknuma, planned to ask for (or steal) a Prowler, which he was provided with.
As of 2552, he was still fighting the Covenant, too far behind their lines to report back to Reach. However, Frederic-104 mentioned Gray Team to be missing since 2551. Though this should not be of too much concern, as it has been stated that Gray Team will sometimes disappear on missions for months, or years, to accomplish them.
Mike was a technical prodigy: he could use any device with expertise after watching it being operated only once. He could also design many tools, such as the EMP bomb used to disable the Kestrel. For his high level of technical intelligence, Mike became a friend to Juliana. He had a rather brash view of life, and enjoyed taking risks simply for the sake of taking risks. He also had a joking nature.
- Mike seems to be careless about any ship he has; according to ONI Officer Hadley, Mike and his team always requested a new ship for every mission, only to lose it in almost every one.
- Unlike other SPARTANS, Mike didn't have a Service tag, until it was revealed in the 2011 edition of the Halo Encyclopedia.