"Counterattack" is the nineteenth episode of the Star Wars: The Clone Wars television series' third season. It first aired on March 4, 2011.
"With freed prisoners in their possession and the brutal warden attempting desperately to thwart them, Obi-Wan and Anakin search for a way out of the Citadel and back to Coruscant. The prison, however, has more traps, perils, and pitfalls in store for them than they had imagined and they must work past their differences if they are to escape. Their bid to board their shuttle fails when heavy weapons fire destroys the escape craft. ARC trooper Echo dies in the blast. The escapees then flee to the caves and call for rescue from the Jedi Temple on Coruscant."
As Anakin Skywalker and his team edge along a magma-filled chasm in the caverns underneath the Citadel, he contacts R2-D2 to prepare their ship for departure. Kenobi, whose team is sneaking through the Citadel's ventilation shafts, is about to rendezvous with the shuttle on a landing platform, but they blunder into a probe droid. Although they manage to destroy it, security hatches begin shutting off the vents, killing yet another clone trooper and slowing the group's progress.
Meanwhile, warden Osi Sobeck is contacted by Count Dooku, who presses him to gain the full information about the Nexus Route. At the same time, Ahsoka Tano, who is leading the team while Skywalker covers their retreat, becomes the object of open criticism by Tarkin, with whose general viewing points about the Jedi's role in the war Skywalker begins to sympathize. They meet a wall which bars their progress, and commando droids armed with force shields attack from behind. Skywalker criticizes Tano for not taking out the wall, stating that Jedi Master Plo Koon would have informed her to do so had she really been assigned to the mission. But Tano manages to blow up the wall and take out the droids, allowing them access to a fuel pipeline which will bring them to their rendezvous point. R2 encounters a hazard of his own as they find the landing platform where they should meet Kenobi's team guarded, but the little droid manages to fool the attending tactical droid K2-B4 that he is actually a prisoner of his droid squad and thus gets inside the fortress.
When Obi-Wan notices the shuttle seemingly abandoned, he senses a trap and attempts to approach it via a detour route, but finds that Sobeck has anticipated this tactic and prepared a welcoming party consisting of a squad of heavily armed battle droids. They are brought before Sobeck as prisoners. In an attempt to get the information, Sobeck executes one of the clone troopers before ordering the security droids to have them interrogated. R2 learns of this, however, and his battle droid team diverts the prisoners to freedom. Skywalker's team likewise runs into a droid force at their exit point, but Skywalker manages to annihilate them by blowing up the pipeline. These escapes plunge Sobeck into difficulties for providing an explanation to Dooku, and in desperation he sends out his remaining forces to the landing platform, where Skywalker's team rejoins with Kenobi's. During the fight with the droids that follows, a commando droid commandeers one of the platform cannons and prepares to fire at the shuttle. Echo attempts to intercept him, but the droid succeeds, destroying the shuttle and critically injuring Echo, and he is presumed dead.
With their immediate means of escape gone, Kenobi calls for retreat, and soon contacts the Jedi Temple, requesting a rescue operation. While the fleet is on its way, the fugitives have no choice but to hole down within the cave system until help arrives, and with Fives throwing a last thoughtful look back to his friend Echo's charred helmet, the group departs to find a hiding place.
During Kenobi's team's capture outside the Citadel, it is noted that the clones were bearing E-5 blaster rifles, the ones that the B1 battle droids use, instead of their usual DC-15A blaster rifles. But later on, during the fight on the landing pad outside, the clones were once again seen using their standard blaster rifles.
In the previous episode, aside from Commander Cody, Captain Rex, Echo, and Fives, there were only four other clones accompanying the rescue team. One was killed by an electromine while another was shocked to death by an electrified wall, leaving only two clones left. However, in this episode, even though the remaining two clones were also killed by a security door and Osi Sobeck respectively, another clone was seen accompanying the team showing that five clones had accompanied the team despite the fact that only four were seen with the team in the previous episode.
During the fight at the landing pad, one of R2-D2's reprogrammed battle droids takes cover with Commander Cody and an unnamed 212th clone trooper. When the three of them take a peak around the corner of their cover, the battle droid is shot by a turret. However, this droid is present in the next episode, despite being killed in this episode.
The moral cited at beginning is a variation of the famous Murphy's Law, which typically states "anything that can go wrong, will go wrong."
ARC Commander Colt can be seen in this episode behind Anakin Skywalker and Captain Wilhuff Tarkin while they are exiting the fuel line. This was likely intended to be either ARC Trooper Fives or Echo.