The Battle TARDIS containing Helen Sinclair and the Eleven crash-landed on Rykerzon, and they were taken as prisoners. During that time, Helen cared for the Eleven and tried to help him control his condition, suppress the voices of his other incarnations. After a number of months, the Eleven killed the Governor and took over the prison.
When the Eighth Doctor and Liv arrived looking for Helen, she was thrilled to see them again, despite the Doctor being skeptical of her. Eventually, the Eleven joined with the Kandyman to take over Colony 23, a plan which was then stopped by the Doctor, Liv and Helen. Helen was then welcomed back on board the TARDIS. (AUDIO: World of Damnation, Sweet Salvation)