Mission to Mustafar (Skywalker and Tano)/Legends

Following the escape of Cad Bane from the Resolute over Devaron, the bounty hunter abducted several children from their homes. The Sith Master Darth Sidious planned on using these children to create an army of force sensitive spies. After finding traces of volcanic ash on Bane's starfighter, the Xanadu Blood, Anakin Skywalker and Ahsoka Tano investigated the mining facilities on Mustafar.

Prelude
Around 22 BBY, the Dark Lord of the Sith Darth Sidious began to rely on the bounty hunter Cad Bane, who was considered to be the most efficient gun-for-hire in the galaxy following the death of renowned Mandalorian Jango Fett. Bane was tasked with stealing a holocron and the kyber memory crystal, which contained a list of every single force potent infant in the galaxy. Bane was then tasked with taking four children on the list to Sidious's lab on Mustafar, a volcanic mining planet in the Outer Rim. Bane succeeded in taking Zinn Toa, a Nautolan, and Wee Dunn, a Rodian, but was arrested during his attempted kidnapping of the Gungan Roo Roo Page. Following a harsh interrogation session, the bounty hunter led Jedi Masters Mace Windu and Obi-Wan Kenobi to his base of operations, though this was a trap set up to ensure his own escape.

While Windu and Kenobi were away on their mission, the Jedi Knight Anakin Skywalker and his Padawan Ahsoka Tano inspected Bane's starfighter, the Xanadu Blood, which had traces of volcanic ash on its hull. While Bane wiped his navigation records, he failed to wipe his fueling records, which revealed the four planets Bane had been in his recent travels: Glee Anselm, Rodia, Mustafar, and Naboo. Mustafar was the only planet on the list that was volcanic, and the Jedi were previously unaware of his travels there. Skywalker and Tano traveled to Mustafar in the Twilight to investigate.

Aftermath
Anakin and Ahsoka brought the children back to the Jedi Temple. Since the Jedi Council wasn't sure of the extent of what the children were subjected to on Mustafar, the Council decided to not return the children to their parents and instead raise them in the Temple, at least for the time being.

Since the entire base sank into the lava, the Jedi were unaware of Darth Sidious's involvement since any evidence of his involvement was destroyed. As Cad Bane escaped from Obi-Wan Kenobi and Mace Windu at Black Stall Station, a follow up interrogation was impossible. Despite this, the children were safe, and the holocron was recovered, with no sign of its information being duplicated. Despite this, Yoda remained concerned about the future of the Jedi order following the incident.

Behind the scenes
New technology introduced during production of season two of Star Wars: The Clone Wars made it possible to fit Mustafar and several other planets depicted in "Children of the Force" into the timespan of a single episode.

Director Dave Filoni was initially opposed to including Mustafar in the show, since that would mean Anakin and the other characters would be aware of the planet's existence during Star Wars Episode III: Revenge of the Sith. George Lucas later persuaded him, clarifying that since Mustafar was a mining planet, it had to have had exports and been an active member of the galactic community.