Doctor Who has spawned three spin-off series' since its return in 2005. Doctor Who sits at the heart of the franchise, with The Sarah Jane Adventures, Class and Torchwood catering for the children, teenager, and adult markets respectively. 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.
the franchise, with
**Mild Spoilers Follow**
DOCTOR WHO: Season One (March - June, 2005)
1.04 Aliens of London (1)
Toshiko Sata appears as an undercover pathologist. Her presence is explained in the Torchwood episode 'Exit Wounds' (2:13).
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 Doctor Who, and secondly, because it's future showrunner Steven Moffat's first Doctor Who 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)
featuring Captain Jack, 'The Parting of the Ways' is particularly
significant as it documents an essential event in Captain Jack's
DOCTOR WHO: Season Two (December, 2005 - July, 2006)
Although Captain Jack doesn't physically appear, there are numerous Torchwood references.
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 Nu-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)
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 Doctor Who
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 Doctor Who.
DOCTOR WHO: Season Three (December, 2006 - June, 2007)
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.
TORCHWOOD: Season Two (January - April, 2008)
2.07 Dead Man Walking
2.08 A Day in the Death
Jones joins the Torchwood team as Medical Officer following the death
of a team member, and 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 Nu-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 Doctor Who, jumps to Torchwood, then The Sarah Jane Adventures, before returning to Doctor Who.
4.02 The Fires of Pompeii
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)
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
Torchwood - Children of Earth
This five part spectacular sits between Doctor Who'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)
Tennant shows up for one last hurrah. As with 'Children of Earth',
chronologically this sits between 'Planet of the Dead' and 'The Waters
of Mars', and features Tennant's final scenes as the Doctor.
4.18 The End of Time (2)
turns up for a quick cameo alongside Russell Tovey (AKA the improbably
named Midshipman Alonso Frame). Sarah Jane Smith also makes an
DOCTOR WHO: Season Five (April - June, 2010)
Russell T. Davies left Doctor Who in 2009, and was replaced as showrunner by Steven Moffat. As a result, both Doctor Who and Torchwood essentially became separate shows. There was one final crossover with The Sarah Jane Adventures, however.
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.)
TORCHWOOD: Miracle Day (July - Sept, 2011)
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'. But as mentioned above, as with season five of Doctor Who, apart from an occasional reference to the Doctor, there's no real continuity or crossover. In fact, the catastrophic global phenomenon at the centre of 'Miracle Day' passes unnoticed in Doctor Who, highlighting the first significant incompatibility between shows.
CLASS: Season One (October 2016)
With the demise of both Torchwood and The Sarah Jane Adventures, all crossover potential appeared to be over. Then in 2016 came the Doctor Who spin-off Class, and crossover shenanigans resumed.
1.01 For Tonight We Might Die
Features an appearance by Peter Capaldi.