I served you for so long, but you let your research be frozen so easily, and the honor and renown we were supposed to get all went away… If I didn’t get at least some money, then it was a waste of my time!Samuel Abraham to David Shield in Two Heroes
Sam is an older, heavier man with short blond hair and blue eyes, which are normally kept closed.
He wears typical business attire, a suit and tie outfit with slacks, suspenders and shoes.
Sam appears to be a goodhearted scientist at first, aiding David throughout his career and protested against I-Island's sponsors wanting them to abandon their work on the Quirk Amplification Device. He proposed the plan to David of staging a fake villain attack so they could recover the device.
However, Sam blamed David for allowing all their hard work to be taken from them. He believed that he deserved a reward for his efforts which is what led him to hire real criminals and turn the device over to Wolfram, expecting monetary compensation. In return, the villain double crossed him, but despite his betrayal, he was still surprised when David jumped to save his life.
Both scientists attend the I-Expo's reception party, but its invaded by Wolfram's Crew. David and Sam are both seemingly taken hostage and escorted to the Storage Room. There, David and Sam work together to unlock the slot holding the Quirk Amplification Device. A device that the two scientists developed in the past but got confiscated by I-Island's higher-ups after they deemed its potential to be too dangerous for society.
David and Sam staged this villain attack to get the Quirk Amplifier back. David believed they hired fake villains, but Melissa catches up to them thanks to Izuku Midoriya and his friends fighting their way through the tower. It turns out that Sam hired real villains and betrayed David's trust to ensure he'd be properly compensated for all his research.
Wolfram appears and decides to keep his end of their deal by shooting Sam. David jumps in the way of the bullet, saving Sam's life. Surprised, Sam asked David why he did so.