The Doctor and Rose Tyler land on the icebound world of Serac where they encounter the Sontaran crew of the Betrothal of Sontar, a mining vessel commanded by Colonel Snathe, whose quest for the "Worldbane", a source of incredible power, has driven him insane. As the Doctor attempts to help Snathe find the Worldbane — mainly in order to recover the TARDIS — Rose befriends Lerox, an unusual Sontaran who possesses a conscience, and who holds the key to saving not only the Doctor and Rose, but the homeworld of Sontar itself.
As this comic predates the Sontarans' first appearance in post-2005 Doctor Who in The Sontaran Stratagem and The Poison Sky, which featured a radical redesign of the Sontaran uniform, the battledress of the Sontarans shown in this comic are reminiscent of those from the classic series.
The Sontaran homeworld is Sontar. This is one of the first Doctor Who stories to indicate this as the name of the Sontarans' homeworld, predating the first on-screen reference to the name in The Sontaran Strategem.