Marcus Caseon

I'm getting off this rock, and you should too.— Marcus Caseon to the Marine (Doom 3)

Marcus — or “Mark” — is one of the UAC's most unlikely survivors. He escaped the events of Doom 3 not through combat skill but through a knack for always being next to the gates of Hell on the safe side.

On The Solar Railway his early career unfolds: he started in 2112 as an eighteen-year-old medic at Amundsen Outpost in Promethei Terra, near the Argent Fracture, and earned the nickname The Man with Nine Lives. His story intersects with Don Ivan Punchatz's Operation Oversight reports and Tim Willits, his ill-fated assistant rejected at Petipa Docks.

Pure chance later places him aboard the Darkstar in time to leave Mars before the invasion — though his PDA found near a severed arm in Mars City leaves that escape in doubt.

PDA Contents

The Man with Nine LivesBy 2145 (Doom 3), Phil Bayly's book, or its film adaptation by Boris Karloff: The Man Who Had 9 Lives, was probably forgotten. Yet, the title perfectly describes the story of Doctor Marcus T. Caseon, or simply "Mark", as his friends know him. Our hero was always in the right place at the right time. Or, more accurately, never in the wrong place at the wrong time. In 2112, he started as an 18-year-old medic at Amundsen Outpost, in the Martian Promethei Terra region near the Argent Fracture. A few years later, he survived the first interdimensional attack from The Well because the monsters could not reach him. A power outage stopped his elevator, trapped between floors. He only heard gunfire, accepting the fabricated pirate attack story.

Background

Outside the Mercury timeline, Marcus T. Caseon (ID 1394-39) is a minor Doom 3 doctor at Mars City who witnessed a spreading epidemic of psychological illness and requested two additional psychiatrists.

After patient Johnathon Wills assaulted him with a scalpel, Caseon decided to leave Mars. At the start of the game he sits at the loading deck urging the Marine to leave too — and departs before the invasion, though his PDA near a severed arm raises questions.

The Mercury Rising portrayal is fan fiction that extends his backstory — it is not official Bethesda lore.

Trivia

• Caseon is not encountered in the Xbox port of Doom 3 — the sitting area is replaced by an FMV, though his PDA remains on revisit.
• Despite waiting at Landing Bay for Dropship 4409, departure timing in-game is ambiguous; The Lost Mission confirms the ship left during the initial invasion.
• His assistant on Mercury, Tim Willits, is a nod to id Software's Tim Willits — unrelated to the real person's fate.

Sources

Want more background? These are the public wiki pages this Codex entry draws from.

Doom Fandom →Doom Wiki →