Series Four, Episode Three - Justice
This episode moves away from Kryten at long last, and it focuses more on looking at Lister in the first half and Rimmer in the second. It introduced the concept of Rogue Simulants as well as containing some interesting concepts.
Lister has space mumps, which results on a large grotesque growth on his head. He laments to Kryten that no one but him has visited him during his time. Kryten slips the fact that a capsule has been taken into Red Dwarf that may contain a woman. He gets up immediately.
The Cat starts the defrosting sequence on the capsule, when Rimmer then informs him that because the capsule was ejected from a prison ship on which the prisoners mutinied, the person in the capsule is either prison guard Barbara Belini or a Rogue Simulant, a sort of super-strong android that has devolved to detest humanity. Worrying about what the capsule may contain, they head to the prison ship from which the capsule was ejected.
As they enter the ship, each is probed to test for criminal activity. While the other three are released (despite Lister confessing to some petty crime) Rimmer is convicted for seveal thousand years for negligence in the fixing of a drive plate 30 million years ago, resulting in the death of all but two life forms on Red Dwarf.
Rimmer is trapped in the "Justice Zone," in which any act that contradicts the law is immediately punished by a similar offence against the offender i.e. Lister tries to burn a sheet at Rimmer's request, and his back sets on fire. Kryten convinces the central computer that Rimmer is extremely incompetent, and therefore is only guilty in his head. After they escape, they find that the capsule has opened and it is a Simulant. He chases them into the Justice Zone, and dies trying to kill Lister.
This is a funny, but thoughtful episode that gives us a look at both characters while still showing us the concept of the Justice Zone and being a tightly scripted affair.
Series Four, Episode Four - White Hole
One of the more absurd and sci-fi episodes of this series, this episode is inventive as well as calling back to earlier series.
Kryten fixes the Series One snarker Talkie Toaster, this time voiced by the original Kryten. Kryten explains why he did so; he has increased his intelligence while shortening his run time. He plans to do the same with Holly. He does so, but instead of increasing her IQ to 6000 as predicted, it raises it to 12000, and she becomes a hologramatic head. Unfortunately, she only has three minutes left, and the ship is powered down.
The crew find out what happened and now know that the power (including oxygen and food recyclers) is limited. After some bickering, they realise that time has started to repeat itself. This is because, as Holly tells them, of a White Hole, which spews time and space into the universe. Lister is able, with help from Kryten, to use explosives from the ship to knock a planet into the White Hole, resetting everything to before they came into its range.