After spending Christmas with his grandmother and aunt in 2004, Matiu worked on time travel equations and sent himself to Christmas Eve, 1953, the time when his grandfather disappeared. Maitu rode on the train to Auckland, and was confronted by the Sixth Doctor, who claimed Maitu was an anachronism.
The train crashed into the river, and Matiu and the Doctor helped rescue the survivors. Matiu found himself working with a young man, and realised it was his grandfather. As they tried to rescue a trapped girl, Matiu's grandfather was swept away by the waters. Matiu woke to find that the Doctor had rescued him and the girl. Having solved the mystery of his grandfather's disappearance, Matiu was ready to return home. (PROSE: Water's Edge)