Walpole

Private Walpole was a UNSC Marine Shock Trooper assigned to the 7th Battalion, 105th ODST Division in 2552.

First Battle of Earth
His unit, second squad, 7th Battalion of the 105th Shock Division, fought during the short First Battle of Earth, and subsequently, during the First Battle of Mombasa in October 2552.

Pelican down
During the battle, he and his squad were in Gunnery Sergeant Pete Stacker's D77-TC Pelican dropship when it was shot down on approach to an area in New Mombasa, Kenya.

After their Pelican was shot down by a Scarab, they reported that the two pilots and O'Brien were killed. They quickly moved out to get better cover, and headed toward Hotel Zanzibar in Old Mombasa.

Moments later, a Plasma grenade had landed on Walpole's helmet. Using quick reflexes, the Marine was able to grab his helmet and hurl it toward a Sangheili Minor's position on higher ground.

There, Gunnery. Sergeant. Stacker and his team saw the charging soldier, only after it had held Jones as a prisoner. Butkis opened fire with an overcharged Plasma Pistol at the Sangheili, as Stacker fired into the Sangheili Minor with his BR55 Battle Rifle.