Doctor Who Finale Spoilers

Spoilers for The Waters of Mars, The Reign of Nightmares and The End of Time.

This is from an interview from BBC America with Russell T Davies:

“The mysterious Ood have told him that his song is ending soon; something deadly is waiting on Mars; Donna’s grandfather, Wilf, is experiencing strange visions; and a powerful psychic warns the Doctor that “He will knock four times…” The end is coming. But will the Doctor, and the human race, survive?”

(Source: Fanatical For Who)

Life, Doctor Who & Combom has details of an interview with David Tennant, Russell T Davies and Euros Lyn. Davies confirms that Wilf and Donna are the main companions in the story. Rose and Sarah Jane make cameo appearances. Something bad happens to Lucy Saxon and The Waters of Mars leads to the finale.