Justice League Unlimited: 1x10
Dark Heart
Most of the League battles with powerful alien nanotechnology but, realize that the waves of self-replicating robots cannot be simply destroyed. The diminutive Atom shrinks himself to stop the robots from the inside.
1 - 1Initiation Jul. 31, 2004
1 - 2For the Man Who Has Everything Aug. 07, 2004
1 - 3Kids' Stuff Aug. 14, 2004
1 - 4Hawk and Dove Aug. 21, 2004
1 - 5This Little Piggy Aug. 28, 2004
1 - 6Fearful Symmetry Sep. 04, 2004
1 - 7The Greatest Story Never Told Sep. 11, 2004
1 - 8The Return Sep. 18, 2004
1 - 9Ultimatum Dec. 04, 2004
1 - 10Dark Heart Dec. 11, 2004
1 - 11Wake the Dead Dec. 18, 2004
1 - 12The Once and Future Thing, Part One: Weird Western Tales Jan. 01, 2005
1 - 13The Once and Future Thing, Part Two: Time, Warped Jan. 29, 2005