S04E12: The Joining (1)
Bruce discovers that Wayne Industries is distributing alien technology across the world, and gains the aid of a mysterious new ally.
Previous Episode 
Season 1
The Bat in the Belfry
S1E1 / 11 Sep 2004
Call of the Cobblepot
S1E2 / 18 Sep 2004
Traction
S1E3 / 25 Sep 2004
The Cat and the Bat
S1E4 / 02 Oct 2004
The Man Who Would Be Bat
S1E5 / 30 Oct 2004
The Big Chill
S1E6 / 06 Nov 2004
The Big Heat
S1E7 / 13 Nov 2004
Q&A
S1E8 / 20 Nov 2004
The Big Dummy
S1E9 / 27 Nov 2004
Topsy Turvy
S1E10 / 05 Feb 2005
Bird of Prey
S1E11 / 12 Feb 2005
The Rubberface of Comedy (1)
S1E12 / 30 Apr 2005
The Clayface of Tragedy (2)
S1E13 / 07 May 2005
Season 2
The Cat, the Bat and the Very Ugly
S2E1 / 14 May 2005
Riddled
S2E2 / 21 May 2005
Fire & Ice
S2E3 / 28 May 2005
The Laughing Bat
S2E4 / 04 Jun 2005
Swamped
S2E5 / 11 Jun 2005
Pets
S2E6 / 18 Jun 2005
Meltdown
S2E7 / 25 Jun 2005
JTV
S2E8 / 09 Jul 2005
Ragdolls to Riches
S2E9 / 16 Jul 2005
The Butler Did It
S2E10 / 20 Aug 2005
Grundy's Night
S2E11 / 27 Aug 2005
Strange Minds
S2E12 / 03 Sep 2005
Night and the City
S2E13 / 10 Sep 2005
Season 3
Batgirl Begins (1)
S3E1 / 17 Sep 2005
Batgirl Begins (2)
S3E2 / 24 Sep 2005
A Dark Knight to Remember
S3E3 / 01 Oct 2005
A Fistful of Felt
S3E4 / 08 Oct 2005
RPM
S3E5 / 05 Nov 2005
Brawn
S3E6 / 12 Nov 2005
The Laughing Cats
S3E7 / 19 Nov 2005
Fleurs du Mal
S3E8 / 26 Nov 2005
Cash For Toys
S3E9 / 04 Feb 2006
The Apprentice
S3E10 / 11 Feb 2006
Thunder
S3E11 / 18 Feb 2006
The Icy Depths
S3E12 / 06 May 2006
Gotham's Ultimate Criminal Mastermind
S3E13 / 13 May 2006
Season 4
A Matter of Family
S4E1 / 23 Sep 2006
Team Penguin
S4E2 / 30 Sep 2006
Clayfaces
S4E3 / 07 Oct 2006
The Everywhere Man
S4E4 / 04 Nov 2006
The Breakout
S4E5 / 11 Nov 2006
Strange New World
S4E6 / 18 Nov 2006
Artifacts
S4E7 / 03 Feb 2007
Seconds
S4E8 / 10 Feb 2007
Riddler's Revenge
S4E9 / 17 Feb 2007
Two of a Kind
S4E10 / 24 Feb 2007
Rumors
S4E11 / 03 Mar 2007
The Joining (1)
S4E12 / 28 Apr 2007
The Joining (2)
S4E13 / 05 May 2007
Season 5
The Batman/Superman Story (1)
S5E1 / 22 Sep 2007
The Batman/Superman Story (2)
S5E2 / 29 Sep 2007
Vertigo
S5E3 / 06 Oct 2007
White Heat
S5E4 / 13 Oct 2007
A Mirror Darkly
S5E5 / 03 Nov 2007
Joker Express
S5E6 / 10 Nov 2007
Ring Toss
S5E7 / 08 Dec 2007
The Metal Face of Comedy
S5E8 / 15 Dec 2007
Attack of the Terrible Trio
S5E9 / 02 Feb 2008
The End of the Batman
S5E10 / 09 Feb 2008
What Goes Up...
S5E11 / 16 Feb 2008
Lost Heroes (1)
S5E12 / 08 Mar 2008
Lost Heroes (2)
S5E13 / 08 Mar 2008
Rino Romano
The Batman (voice)
Evan Sabara
Robin (voice)
Danielle Judovits
Batgirl (voice)
