"Once a Handmaiden..." is the eighteenth episode of Season 3, aired on the twenty-third of February at 7:06 to 7:28 am.
- Kiera and Catalina (cameo)
- Adira (cameo)
- Hector (cameo)
- Xavier (cameo)
- Nigel (cameo)
- Mrs. Crowley (cameo)
- Monty (cameo)
- Quirin (cameo)
- King Frederic (cameo)
- Queen Arianna (cameo)
- Pete and Stan (cameo)
- Gothel (flashback via hand-mirror)
- Faith (vocal debut)
- Corona Village
- Cassandra's Stronghold
- Corona Castle
- Old Corona
- The Throne Room
- Snuggly Duckling
- Vardaros (mentioned)
- Spire Vault (mentioned)
Objects of Supreme Power
- Eugene's Sword
- Project Obsidian
- Like "Happiness Is..." the title is a partial popular quote
- Cassandra finds the broken piece of mirror that Zhan Tiri threw away in A Tale of Two Sisters and Cassandra is mad at Zhan Tiri for manipulating Cassandra's memory by taking a portion of the mirror and tossing it away.
- This is the second time Varian is taking matters into his own hands. The first time that he took matters into his own hands was Queen for a Day.
- Cassandra realized that Rapunzel was telling the truth about Mother Gothel because she never loved Cassandra and Rapunzel but only her youthful appearance which was what Rapunzel telling Cassandra in A Tale of Two Sisters.
- The way Varian attacks Cassandra to protect the kingdom from her in this episode is similar to way Varian attacks the automaton with his alchemy to protect Rapunzel in The Alchemist Returns.
- The way Eugene bumps his shoulder with Varian's shoulder in this episode is similar to the way Eugene bumps his elbow with Lance's elbow in Big Brothers of Corona.
- Rapunzel's new handmaiden is revealed to be Faith.
- This is the eighth episode where Varian wears his goggles on his eyes. The other seven episodes that Varian wore his goggles are Queen for a Day, The Alchemist Returns, Secret of the Sundrop, Rapunzel's Return, Day of the Animals, Cassandra's Revenge and Flynnpostor.
- The way Lance tells Eugene that everyone has to fall back in this episode when Cassandra and the brainwashed Adira and Hector defeated Lance, Varian, Eugene, King Edmund and the citzens of Corona in this episode is similar to the way Cassandra and her adopted father tell each other to stand down during the nightmare at the beginning of Flynnpostor, is similar to the way Rapunzel wants Varian to tell Andrew and the Saporians to stand down during the first half of Rapunzel's Return is similar to the way Clementine tells Varian to stand down when he is going to free Pascal from the bubble during the second half of Rapunzel's Return and it is also similar to the way the Captain of the Guards told Pete, Stan and the other guards to stand down in Cassandra v. Eugene.
- The way Cassandra wants to make amends with Rapunzel in this episode after Cassandra found out that the Enchanted Girl is one of Zhan Tiri's many forms but Cassandra attacks Varian, Eugene, Lance, Shorty, Monty, Feldspar, Pete, Stan, King Edmund and the other citizens of Corona alongside the brainwashed Adira and Hector when she realized that Zhan Tiri was right about Project Obsidian is similar to the way Rapunzel wanted to make amends with Varian in The Alchemist Returns by helping him taking the Sun Drop flower from the royal vault but when Varian and Rapunzel arrived at the royal vault, Varian grabbed it before he revealed his true agenda to Rapunzel and Pascal then Varian told Rapunzel that everyone turned their back on him.
- The way Rapunzel tells Varian that no one needs to attack Cassandra while she wants to talk to Cassandra after Zhan Tiri removes the cloak is similar to the way Rapunzel told her dad that he shouldn't be too hard on Varian after he was arrested and sent to the dungeon when he was defeated in Secret of the Sun Drop.
- The way Varian steps away from Eugene at the beginning of this episode is similar to the way Varian stepped away from hearing another one of Xavier's legends at the tomb in The Lost Treasure of Herz Der Sonne with everyone.
- The way Varian, Eugene, Lance, King Edmund and the people of Corona are falling back to the Snuggly Duckling after Cassandra attacks them with her black rocks alongside the brainwashed Adira and Hector is similar to the way Rapunzel and her parents ran outside of Varian's home when Varian attacked the royal family in Secret of the Sun Drop.
- This is the sixth time the closing theme "More of Me" is not featured, the previous being "Queen for a Day", "part one of Secret of the Sun Drop ", "Rapunzel and the Great Tree", "Destinies Collides", part one of "Rapunzel's Return" and "Cassandra's Revenge".
- Cassandra reveals to Zhan Tiri that she is afraid of Rapunzel not forgiving her.
- Shorty flirting with Cassandra is a reference to the movie when he flirted with Gothel.
- Quirin is the only Brotherhood member not affected by the Mind Trap.
- King Edmund is also unaffected by the Mind Trap.
- This is the second time that Catalina doesn't speak in the episode. The first time that she doesn't in the episode was The King and Queen of Hearts. This is the only episode that Kiera doesn't speak.
- Eugene is the fourth person that tried to reason with Cassandra in this episode and the other three people that tried to reason with Cassandra are Varian in Cassandra's Revenge, the Captain of the Guard in Islands Apart and Rapunzel in Rapunzel's Return but Cassandra wouldn't listen to reason when Rapunzel, the Captain of the Guard, Varian and Eugene tried to tell Cassandra to stop her vengeful ways.
- The way Eugene tells everyone to fall back after he, Varian, Lance, King Edmund and the people of Corona are defeated by Cassandra with the help of the brainwashed Adira and Hector is similar to the way Eugene told Rapunzel to leave with him and their other friends after being defeated by Varian, Andrew and the Saporians in Rapunzel's Return.
- The way Rapunzel is breathing in the potion that Cassandra threw to the ground after Cassandra realized that Zhan Tiri was right about Project Obsidian is similar to the way Rapunzel breathed in the alchemy that Varian threw to the ground in The Alchemist Returns to escape.
- The way Cassandra realized what she did to her home and her friends and Rapunzel is similar to the way Varian showed deep remorse and shame for his actions that he did when he was an antagonist in Secret of the Sun Drop.
- The way Rapunzel is mad after she saw that Cassandra has taken over Corona is similar to the way Varian is mad when he turns around to face Queen Arianna after he saw the Corona army outside in Secret of the Sun Drop.
- The way Cassandra is taking over Corona by forcing Rapunzel and her friends and her parents and the people of Corona to leave is similar to the way Varian, Andrew and the Saporians took over Corona in Rapunzel's Return by forcing Rapunzel and her friends to leave before Varian found out the true colors of Andrew and the Saporians.
- The way Rapunzel holds Cassandra's wrist iin this episode is similar to the way Varian holds Cassandra's wrist during the song Nothing Left to Lose in Cassandra's Revenge
- The way Eugene puts his hand out to Cassandra is similar to the way Rapunzel puts her hand out to Cassandra for a temporary truce in A Tale of Two Sisters.
- This is the second episode Varian is reaching out to Cassandra, the first was Cassandra's Revenge via "Nothing Left to Lose".
- Varian refers to himself and Eugene "Team Awesome" again since What the Hair?!.
- Rapunzel and Eugene make a reference to when Eugene almost married Stalyan in Beyond the Corona Walls.
- Cassandra becomes the second person to be encased by Varian's amber solution after Quirin in Queen for a Day. But she manages to escape using the black rocks unlike Quirin when he didn't want Varian to help free him before being encased.
- The way Cassandra throws the potion to the ground after taking it out of her bag is similar to the way Varian threw his alchemy to the ground after taking it out of his bag to escape the castle from the guards, Eugene and Cassandra before being captured in The Alchemist Returns and it is also similar to the way Varian threw his alchemy at Maximus to make him dizzy in Rapunzel's Return.
- This is the second episode Eugene says Cassandra is like a sister to him, the first episode where Eugene said Cassandra has become like a sister to him was Destinies Collide.
- Adira and Hector attack Corona after they fall under the influence of the Mind Trap Talisman that Cassandra previously acquired in Race to the Spire.
- Cassandra's line, "Fine. You want me to be the bad guy, now I'm the bad guy." are the exact same words Mother Gothel said when she finally revealed her true nature to Rapunzel in Tangled.
- This is the third episode the Goodwill Festival that takes place during the annual Goodwill Festival, the first and second times being Rapunzel's Enemy and Goodbye and Goodwill.
- The way Kiera and Catalina have minor appearances in this episode is similar to the way they and Varian had minor apperances in The King and Queen of Hearts and it is similar to the way Cassandra had minor appearances in Max's Enemy, Lost and Found, Return of the King, Who's Afraid of the Big, Bad Wolf? and it is also similar to way Varian has a minor appearance in Not in the Mood.
- When Lance says he doesn't want to fight Adira is similar to the way when Rapunzel said she doesn't want to fight Cassandra at the Demanitus Chamber and at the stronghold but Cassandra forces Rapunzel to fight for Eugene because Rapunzel wouldn't fight Cassandra in Cassandra's Revenge.
- This is the third episode where Rapunzel is knocked unconscious. The first two times that she was knocked unconscious are The Alchemist Returns and A Tale of Two Sisters.
- The way Cassandra walks backwards when she says Rapunzel, I want to believe you is similar to the way Varian walked backwards toward the wall when he is saying I should have not said that out loud in Cassandra's Revenge.
- Cassandra makes a reference to when Eugene mixed up the bim- and dim-berries in Rapunzel's Enemy.
- Cassandra succeeds in taking over Corona which was Rapunzel's greatest fear in Be Very Afraid!.
- The way Cassandra feels down in this episode is similar to the way Catalina was feeling down in Who's Afraid of the Big, Bad Wolf? is similar to the way Varian was feeling down in Rapunzel's Return.
- The captions describe the way owl hoots at Cass as "disapprovingly"
- Project Obsidian disappeared but is replaced with a different one when Varian is shown to be wearing his outfit, apron, gloves and shoes from season one and at the near end of Rapunzel's Return when he is sitting on Fidella before a guard comes to tell Eugene that Cassandra is inside Corona to attack Rapunzel.