Medusa Cascade

The Medusa Cascade was a location where there was a time rift. At some point, the Doctor closed the rift in time and space. (DW: Last of the Time Lords)


 * Based on the Master's familiarity with the event, he was most likely involved, possibly opening the time rift himself.

Evelina, who can see the future, mentions the Medusa Cascade when commenting on The Doctor saying "He burns like the fires of the Cascade of Medusa herself". (DW: The Fires of Pompeii)

Behind the Scenes
In an interview with DWM, Russell T. Davies claimed the Medusa Cascade would play a major part In Series 4 and "come back to haunt us"