Red Dwarf Season 4 Episode 5

Dimension Jump

An alternate reality version of Rimmer literally crashes into his alter-ego while testing a dimension-jumping spacecraft. With Starbug downed after the collision, the daring, dashing Ace Rimmer attempts a one-man rescue, unaware that his doppelganger is, in this reality, an intolerable coward. Neither a broken arm nor hostile, jealous hologram can keep him from his duty, but when the company is this hopeless, even a hero finds it hard to keep his chin up.