Story arc

The link to the series is like the theme.
 * Series 1 - Bad Wolf (DW: Bad Wolf)
 * Series 2 - Torchwood
 * Series 3 - Harold Saxon (DW: The Sound Of Drums - Last Of The Time Lords)
 * Series 4 - Doctor Donna (DW: Planet Of The Ood)
 * Series 5 - Amy's Crack In The Wall (DW: The Eleventh Hour)