A comrade and friend of Jeffrey Sinclair, Mitchell flew on Sinclair's 361st Tactical Fighter Squadron during the Battle of the Line in 2248. During the opening skirmish of the battle, the squadron encountered a wing of Minbari Nial class fighters. When one of the fighters pursued Sinclair's ship, Mitchell broke formation to assist him. Moments later, a fleet of Minbari Warcruisers exited out of hyperspace and ambushed the Starfury squadron. One of the cruisers shot Mitchell down. His death would haunt Sinclair for many years afterwards.