Doctor Who: Doom's Day. A Doctor In The House?

Set in the 51st Century, a solitary assassin embarks on a desperate quest for survival, relying on the enigmatic Doctor for salvation. Armed with a vortex manipulator, she navigates perilous encounters, including an alliance with the wicked Missy. With each passing hour, she faces thrilling adventures and the looming threat of death, highlighting the urgency of her mission and the unpredictable nature of time travel.