Mass Effect: Wake Up, and Smell the Ashes...

Dr. Micheal Edward Lupin was at Ground Zero during The Black Mesa Incident. He had disappeared when he and Gordon Freeman went through a portal to stop The Nihilanth, only to re-appear 20 Years Later, in a world broken, enslaved by the interdimensional empire known as The Combine.

He was there when Eli Vance died.

In a fit of pure rage, he chased after the Combine Advisors that killed and extracted the information in Eli's head, and managed to kill them all. He began a lone crusade against The Combine's attempt to regain control of Earth, becoming the Martyr of Humanity, re-igniting the Planet's Fire, leading to The Combine's utter defeat, and a new age began.

On May 16, 2148, over 143 years since the Resonance Cascade, exactly, Explorers discovered the remains of an Ancient Civilization on Mars. In the decades that followed, new, startling discoveries were made, launching Humanity into space, eventually coming across an artifact that warped Time and Space to allow ships to reach far, distant stars. The Civilizations of The Galaxy called it...

MASS EFFECT

Over a month after the devastating Geth Attack on the Citadel, Commander Cassidy Rose Shepard was dispatched to find and wipe out any remaining Geth Ships in Citadel Space... they instead found the remains of a Collector ship, and are attacked by an enemy long since gone...

2 Years Later, Dr. Lupin re-appears...