By Samantha Simon
Updated Dec 14, 2015 @ 11:30 am
Credit: theroyalsone/Instagram

One rainbow dress can change the world—at least that was the case on last night's episode of The Royals. After Princess Eleanor (Alexandra Park) is caught kissing her new girlfriend, Mandy (Sarah Dumont)—who, unbeknownst to the princess, is actually Jasper's secret partner-in-crime, Samantha—photos of the pair are splashed across the pages of every tabloid. Unsurprisingly, Queen Helena (Elizabeth Hurley) isn't pleased with Eleanor's new fling. So, to aggravate her mom even more, the princess decides to make a scene—and one very public statement.

She and Mandy arrive together for a knighting ceremony at the palace, making their official debut as an item. Eleanor is in no way trying to keep her new relationship on the DL, and her rainbow dress and purple ombre locks bring her the attention she so craves. "It's a standout outfit for sure—and I think everyone will be shocked when they see it," the show's costume designer, Rachel Walsh, recently told InStyle. "Eleanor never dresses like this, but she totally rocks it and pulls it off with some great shoes and accessories." The princess's look is about much more than fashion, though. "She wears this dress for a reason, and we were really conscious that you'd still believe Eleanor would wear it," said Walsh, adding that "she's been a lot more experimental with her wardrobe this year."

Of course, that's not the only thing the princess is experimenting with lately. But whether or not her feelings for Mandy are the real deal remains TBD. "She's quite a playful character, but she's also such a strong young woman and role model," said Walsh. "She's sassy, confident, and she doesn't care what other people think of her." While that might be true when it comes to the public, there are still a few people whose opinions the princess does value, whether she wants to admit it or not: her mother's and her grandmother's, the Grand Duchess Alexandra of Oxford (Joan Collins).

Credit: Courtesy E!

After Eleanor's PDA-packed day, her grandmother brings her a present—along with some words of wisdom. As she gifts Eleanor with a pair of diamond earrings, the Grand Duchess tells her granddaughter that she and diamonds, "like gin and tonic, are destined for each other." But while Eleanor's grandma—who earlier in the episode announced that she's spent her fair share of time in the "questioning" phase of the LGBTQ community—tells the princess that she's proud of her, she also warns that she should only be taking a stand for the right reasons, and that doesn't include trying to upset her mom.

Credit: Courtesy

Speaking of the queen, she's trying to keep order in the palace—and she's looking damn good while doing it. She takes a softer approach to her look for the knighting ceremony, opting to forgo her usual bold colorful shifts. "We designed a beautiful, pale, golden oyster lace dress for the queen," said Walsh. "We wanted to start this journey with her looking quite pale, and it's definitely a different look for her." Helena is switching up more than just her wardrobe—she's also changing who's in her inner circle. No longer trusting her former right-hand man Lucius (Andrew Bicknell), she teams up with the palace's Head of Security, Ted Pryce (Oliver Milburn), to find out what happened to her true love, Captain Alistair Lacey (Noah Huntley). And when the queen does get her answer, it's not the one she was hoping for.

Helena finds out that Lucius had Alistair killed in order to tie up one of the final "loose ends" from last season's paternity scandal. This revelation shocks the queen, who has only ever showed true human-like emotion when it came to her forbidden affair. Helena has Lucius taken away, and Pryce sees this as his chance to cross off another murder as solved—and, presumably, to keep himself off the suspect list for good. He convinces Lucius to confess to murdering King Simon, even though he didn't. It's Lucius's final act of grace for the queen, who instantly sees right through his admission but lets him go down for the crime all the same.

Credit: Courtesy E!

Pryce may be sneaky, but he isn't the only scheming security staffer. Jasper (Tom Austen) is freaking out now that Mandy-slash-Samantha is spending the majority of her days in Eleanor's bed, and he's not just jealous that two of his former girlfriends have found each other. Jasper's worries go much deeper than that. He's nervous that the princess's latest publicity stunt will reveal Mandy's true identity and, with it, the fact that Jasper is her co-conspirator.

Credit: theroyalsone/Instagram

Unfortunately for Jasper, Mandy is the one in control now. After a series of meetings in the palace's underground tunnels, she reveals her new plan for the pair to steal the royal diamond—which, we now know, is what brought Jasper across the pond in the first place. The heist will be going down at the prince and princess's upcoming birthday celebration—and that diamond is going to make quite the party favor.

Tune in to The Royals on Sundays at 10 p.m. ET on E!