Doctor Who has spawned two spin-off series' since its return in 2005.
Doctor Who sits at the heart of the franchise, with
The Sarah Jane Adventures and
Torchwood catering for the children and adult ends of the market. The question is: how does it all fit together? Below is a chronology of the show's main crossover episodes. It's by no means exhaustive; but what follows
should be enough to give the new viewer a rough idea of what to expect, and the order in which to expect it.
**Mild Spoilers Follow**
DOCTOR WHO -- SEASON ONE (March - June, 2005)
1.09 The Empty Child (1)
1.10 The Doctor Dances (2)
A cool two parter -- firstly, because it's Captain Jack's first appearance in
DW; secondly, because it's future showrunner Steven Moffat's first
DW script. (Excluding spoof "Doctor Who and the Curse of Fatal Death".) And what a belter it is. Are you my mummy?
1.11 Boom Town
1.12 Bad Wolf (1)
1.13 The Parting of the Ways (2)
Also featuring Captain Jack. “The Parting of the Ways” is significant as it documents an essential event in Captain Jack's history.
DOCTOR WHO -- SEASON TWO (December, 2005 - July, 2006)
Although Captain Jack doesn't physically appear, there are numerous
TW references in season two.
2.02 Tooth and Claw
Queen Victoria orders the formation of the Torchwood Institute; its purpose to defend the United Kingdom from alien attack.
2.03 School Reunion
Not a series crossover per se, but an example of
Classic Who crossing over with
New Who. Third/Fourth Doctor's companion Sarah Jane Smith makes her first appearance -- and totally steals the show. Tin mutt K9 also has a cameo.
2.12 Army of Ghosts (1)
2.13 Doomsday (2)
Our first glimpse of the Torchwood Institute. Also worthy of mention is Freema Agyeman's first appearance as Adeola Oshodi, cousin of Martha Jones. Freema later (and some would say bizarrely) goes on to play Martha Jones in season three.
TORCHWOOD -- SEASON ONE (2006-2007)
Torchwood's first season proper! Surprisingly, there are no
DW crossovers; just lots of swearing and sex. Unless, of course, you count the TARDIS as a character -- and after "The Doctor's Wife", who's to say she isn't ? The sexy beast!
1.13 End of Days
The TARDIS materialises, Jack runs towards it, and ends up in season three of
DW.
DOCTOR WHO -- SEASON THREE (December, 2006 - June, 2007)
3.11 Utopia.
Jack finally catches up with the Doctor and confronts him about the events of “The Parting of the Ways”.
3.12 The Sound of Drums (1)
3.13 Last of the Time Lords (2)
Jack and Martha leave the TARDIS.
THE SARAH JANE ADVENTURES -- SEASON ONE (Jan - November, 2007)
No Crossovers.
TORCHWOOD -- SEASON TWO (January - April, 2008)
2.06 Reset
2.07 Dead Man Walking
2.08 A Day in the Death
Martha Jones joins the Torchwood team as Medical Officer following the death of a team member. She sticks around for three episodes.
THE SARAH JANE ADVENTURES -- SEASON TWO (September - December, 2008)
2.11 Enemy of the Bane (1)
2.12 Enemy of the Bane (2)
A
Classic Who crossover, with the Brig himself, Nicholas Courtney, turning up to give the Bane a ruddy good kick up the bottom. This was originally intended to be a
New Who crossover featuring Martha Jones, but Freema was too busy working on
Law & Order: UK, and was subbed at the last minute.
DOCTOR WHO -- SEASON FOUR (December, 2007 - January, 2010)/TORCHWOOD -- CHILDREN OF EARTH (July, 2009)/THE SARAH JANE ADVENTURES -- SEASON THREE (October - November, 2009)
All three shows intermingled during 2009. The chronology starts off with
DW, jumps to
TW, then
SJA, before returning to
DW.
Doctor Who:
4.02 The Fires of Pompeii
Notable for Karen Gillan's first appearance as a soothsayer. Karen returned in season five as the Eleventh Doctor's companion, Amy. Not exactly a crossover; I just felt compelled to mention it.
4.04 The Sontaran Strategem (1)
4.05 The Poison Sky (2)
4.06 The Doctor's Daughter
Martha Jones returns for a three episode story arc, before vanishing again, only to reappear in the two-part season finale.
4.12 The Stolen Earth (1)
4.13 Journey's End (2)
This should have been a crossover made in heaven: Captain Jack makes his now customary cameo, and is joined by Sarah Jane Smith for a triple show collision. Even Martha shows up. Unfortunately, it's all a bit of a lame duck.
Torchwood - Children of Earth:
This five part spectacular sits between
DW's “Planet of the Dead” and "The Waters of Mars". But there's no essential continuity, so its placing is pretty much unimportant.
The Sarah Jane Adventures:
3.05 The Wedding of Sarah Jane Smith (1)
3.06 The Wedding of Sarah Jane Smith (2)
David Tennant shows up for one last hurrah. Chronologically, this two-parter sits between "Planet of the Dead" and "The Waters of Mars", and features Tennant's final scenes as the Doctor.
Doctor Who:
4.18 The End of Time (2)
Jack turns up for a quick cameo alongside Russell Tovey (AKA the improbably named Midshipman Alonso Frame). Sarah Jane Smith also makes an appearance.
DOCTOR WHO -- SEASON FIVE (April - June, 2010)
Russell T. Davies left
DW in 2009, and was replaced as showrunner by Steven Moffat. As a result, both
DW and
TW essentially became separate shows. There were no
TW crossovers in season five; but there
was a
SJA crossover.
THE SARAH JANE ADVENTURES -- SEASON FOUR (October - November, 2010)
4.05 Death of the Doctor (1)
4.06 Death of the Doctor (2)
Matt Smith turns up in an episode also featuring Katy Manning. (One of Worzel's ex-companions.)
DOCTOR WHO -- SEASON SIX (December, 2010 - October, 2011)
Again, no crossovers.
TORCHWOOD -- MIRACLE DAY (July - Sept, 2011)
TW season four appears chronologically after "A Good Man Goes to War", and runs concurrently with "Let's Kill Hitler", "Night Terrors" and "The Girl Who Waited". As with season five, apart from an occasional reference to the Doctor, there's no real continuity or crossover.
THE SARAH JANE ADVENTURES -- SEASON FIVE (October, 2011)
As of yet, no crossover.