The BBC Press Office have updated their television schedule, and the official summaries for episode 5 and 6 - The Poison Sky and The Doctor's Daughter - are now available (here for PS, here for DD). You can read the summaries below:
The Sontarans activate their masterplan and begin to choke the whole of planet Earth, as Russell T Davies's Bafta Award-winning time-travelling drama continues. UNIT is left defenceless, with a traitor in their ranks. And as interplanetary war edges closer, the Doctor has to fight to keep both Martha and Donna alive – but will he have to make the ultimate sacrifice?
The Doctor meets the most important woman of his life on the distant planet Messaline, in the middle of an endless war, as Russell T Davies's Bafta Award-winning time-travelling drama continues. But as General Cobb threatens genocide, and Martha is kidnapped by the Hath, the Doctor faces an even greater battle – can he find peace with his own child?The Poison Sky airs May 3 and The Doctor's Daughter airs May 10 on BBC1.