This story is a sequel to Dear Derpy

The Doctor has to leave another one of his companions. But this one is different. This mare was just like the cross eyed mare that he left behind in the same world that he couldn't find. But a secret leads to a key happiness for the Doctor. Rose knows that he was upset and she tries to make it up to him, but when they said goodbye, this was her chance to tell him the secret that she was keeping from him. Can she tell him? Or will she tell him too late? *based off of the final episode of Rose Tyler*