Questus

From Tardis Wiki, the free Doctor Who reference

Questus was a planet.

After escaping Kells, Lucie Miller and the Monk went there, where the Monk had travelled back in time to kill the parents of a dictator in an avalanche to prevent the dictator's birth. At this point, after being dragged out of the avalanche, Lucie tired of the Monk's meddling and began to consider his actions amoral, to the point of calling him a murderer. After this, the Monk "dumped" her on Deimos Moonbase in the 23rd century, deliberately placing her there in an attempt to grab the Eighth Doctor's attention. (AUDIOThe Resurrection of Mars)