The conversation Ahsoka has with Rex at the start of the episode is a mirror of their very first conversation they had, as seen in the Star Wars: The Clone Wars feature.

It was the script to this episode that first established the naming convention for the Inquisitors, with Eighth Brother the first one named. Seventh Sister and Fifth Brother were then retroactively renamed at the start of the season, having been known only as Female Inquisitor and Male Inquisitors in the scripts.

Along the patterns inscripted on the base of the Malachor Sith temple is the ancient writing first designed by Ralph McQuarrie that was also seen on the Lothal Jedi temple.

During the development of this episode, Dave Filoni drew heavily from mythological depictions of the internal underworld, delineating specific levels of descent.

The petrified bodies that line the battlefield of Malachor were inspired by the impressions of figures left behind after the devastation of ancient Pompeii.

The ancient “claymore lightsaber” is a reference to the design made famous by Kylo Ren in The Force Awakens. The Force Awakens: The Visual Dictionary hinted at its inclusion by noting that Kylo’s weapon is based on an ancient design that dates back to the Great Scourge of Malachor.

The Eighth Brother Inquisitor is a Terrelian Jango Jumper, a species first seen in Star Wars: The Clone Wars.

Although the final cut of Return of the Jedi has an eyebrow-less unhelmeted Darth Vader, to better read in animation, the animation model has the dark brow visible through the cracked helmet.

The first explorations of this story had a duel between Maul and Vader in the Second Act, but the evolution of the script and the realization that it was one duel too many spared Maul that confrontation.

In the original outline, the infernal machine at the heart of the Sith Temple actually completes its firing cycle. In the finished episode, the removal of the holocron cuts the cycle short.

In the unfinished “Crystal Crisis on Utapau” arc from Star Wars: The Clone Wars, Yoda makes mention of ancient Sith superweapons powered by kyber crystals. The infernal machine of the Sith temple is a rare example of an intact one.

The original script had Maul say this about Malachor: “Palpatine brought me here when I was a boy. My Master had long studied the ancient dark arts, he sought out relics, and locations like this.”