Just after finally defeating the Sontarans on modern-day Earth, the Doctor's TARDIS takes the Tenth Doctor, Donna Noble and Martha Jones on an unexpected trip to the barren planet Messaline. Arriving right in the middle of a war between humans and Hath, the Doctor meets someone he thought he never would: his daughter. Can the Doctor accept this clone as his offspring, and can he stop the war before it all ends in massacre on both sides?

"It's not what I'd call natural parenting"