Susan’s War, Vol. 2: Family Ties

No Gallifreyan was safe from the Time War. While the Doctor resisted the call, his granddaughter Susan did her duty and signed up to fight the growing Dalek threat.

2.1 The Lost Son by Sarah Cassidy - Still reeling from meeting her Grandfather back on Earth, Susan is assigned to assist a mother in search of her son. Priestess Vesselina is the new ruler of her world, and someone Gallifrey is keen to recruit as an ally. But strange forces are at work on Materos, and Susan's empathy becomes a weapon to be used against her.

2.2 The Golden Child by Peter Anghelides - A key ally to Gallifrey has winked out of existence. When Susan investigates the disappearance of this gifted politician and strategist, she finds someone else is also interested in the changed timeline. The interloper is her grandfather. But this version of the Doctor is from the future of the Time War, and he's not the man Susan remembers.