Maruthea was a planet-sized space station in the dead centre of the space-time vortex, supposedly an impossibility. (COMIC: Party Animals, The Incomplete Death's Head)
The Seventh Doctor repeatedly tried to travel to Maruthea, but "the old girl led him astray" and he instead ended up in various other places, including Mekrom, (COMIC: Echoes of the Mogor!) Tojana, (COMIC: Time and Tide) London, (COMIC: Invaders from Gantac!) Archimedes, (PROSE: The Infinity Season) and Hell. (COMIC: Nemesis of the Daleks)
The Doctor and Ace eventually reached the planet in time for Bonjaxx's birthday in his bar. A future incarnation of the Doctor and his companion Ria were also there for the party, among various individuals the Doctor had encountered before. (COMIC: Party Animals, The Incomplete Death's Head)
After being flung into the time vortex with the explosion of the Dogbolter Temporal Rocket, (COMIC: Time Bomb!) Hob settled on Maruthea in search of Josiah W. Dogbolter. Over the course of three million years, he set up the Death's Head Interactive Archive in an attempt to locate Death's Head, thinking the freelance peacekeeping agent would know his master's whereabouts. Death's Head II and his partner Tuck materialised on Maruthea at the same time as Bonjaxx's party, and were forced to either experience or watch the events of Death's Head's life, respectively. Death's Head II and his earlier self (who was also present at the party) incapacitated Hob. The Seventh Doctor arrived just in time to stop the earlier Death's Head from killing his future self, revealing he was actually the one who made sure Death's Head II and Tuck would arrive on Maruthea to stop Hob from killing the first Death's Head. (COMIC: The Incomplete Death's Head)