Warning: There are spoilers ahead for Doctor Who season 15, episode 6.

The Rani has returned to the Whoniverse for Doctor Who season 15, bringing her complicated relationship with the Doctor back to the forefront of the long-running sci-fi series. Ever since the 2023 Christmas special "The Church on Ruby Road" first aired, audiences have been intrigued by Anita Dobson's Mrs. Flood, a seemingly ordinary neighbor who possesses knowledge beyond any ordinary human should and ambitions to rewrite reality. Her presence expanded in season 15, as she pursues the Fifteenth Doctor (Ncuti Gatwa) and Belinda Chandra (Varada Sethu) on Belinda's extended journey home to the present day.

Despite keeping her distance, Flood's latest appearance sees her caught up in the crisis at the 803rd Intergalactic Song Contest, as she is ejected into the cold void of space. Even though the Doctor saves the day and Flood is able to be recovered alongside the rest of the contest's attendees, her double brainstem is frozen, which should have led to her demise. However, Flood is saved by her Time Lord physiology, leading to her surprise bigeneration as she splits between her current self and a new incarnation (Archie Panjabi), who reveals herself to be the Rani.

The Rani And The Doctor Were Childhood Friends

The Two Time Lords Began Life As The Closest Friends

Despite immediately positioning herself as a foe to the Doctor, the Rani did once have a close connection to the Time Lord during their childhood. Long ago on Gallifrey, two children known as Theta Sigma and Ushas, who would later take on the titles of The Doctor and Rani, were childhood friends. Growing up together, the pair would eventually find themselves following in Gallifreyan tradition, facing the Untempered Schism before entering their education at the Prydonian Academy.

At the Academy, Ushas excelled in most of her subjects, but had an incredible affinity for chemistry, and most importantly of all, conducting several experiments to further her curiosity. She also found herself entering the ranks of the Deca alongside Theta Sigma and their mutual friend, Koschei, a group of ten rebellious Time Lords who hoped to change their world. However, the Deca's unity couldn't last, as fate saw them traveling on very different paths.

One by one, the group's went their separate ways. Theta Sigma would assume the mantle of the Doctor and run away from Gallifrey in a broken TARDIS, with Koschei becoming the Master and following shortly after. Ushas, who had by that time assumed her own name of the Rani, would instead be forced into exile after a rampant experiment of hers caused terror for the Lord President Pandad IV. After leaving her homeworld behind, the Rani would find herself landing on the world of Miasimia Goria.

The Rani Became One Of The Universe's Most Wanted Villains

The Rani's Ambitions Saw Her Turn Entire Worlds Into Her Experiments

As the Rani began to expand her influence over Miasimia Goria, she began to build her own reputation. While beginning to spread her influence over the planet and assuming leadership of the world, the Rani became known across the galaxy for her twisted experiments, sourcing several lifeforms from Earth and beyond to add to her inventory. As she became regarded as the second most-wanted criminal in the universe, second only to the Master, the Rani began one of her most notable experiments.

Her great experiment saw her set out to try and raise the awareness of the Miasimia Gorians by depriving them of sleep, only for the results to leave the populace rampant. In order to settle the unrest against her, the Rani set out to harvest chemicals from human minds that enable the mind to sleep in hopes of applying it to her own subjects. It was one of these harvesting missions that reunited her with the Doctor and Master in her debut in 1985's "The Mark of the Rani."

The Rani chose to abduct humans from times of great unrest to hide her plot, such as the siege of Troy.

As the Sixth Doctor (Colin Baker) and Peri (Nicola Bryant) materialize in the 19th-century mining town of Killingworth, the pair not only encounter the Rani, portrayed by Kate O'Mara, but the Tremas incarnation of The Master (Anthony Ainley) as he embarked on his own scheme. While the Doctor put a stop to their plans, the pair attempted to escape in the Rani's TARDIS. However, a quick gambit made by the Doctor forced one of the Rani's Tyrannosaurus Rex embryos to rapidly grow, almost crushing the pair and forcing the Master to hijack the control room and eject it from the main vessel.

After spending some time adrift and seeing the Sixth Doctor thwart her attempt to experiment with control of her regeneration cycle, the Rani would exact revenge on her former friend in 1987's "Time and the Rani." Having allied with the Tetraps to assume control of Lakertya for a new experiment, the Rani set her sights on the Sixth Doctor, ambushing him while in-flight in the TARDIS and leading to him sustaining fatal injuries. The assault led to the Doctor regenerating into his Seventh incarnation (Sylvester McCoy), where the Rani saw a new opportunity.

Posing as companion Mel Bush (Bonnie Langford), the Rani attempted to manipulate the still-recovering Doctor into aiding her plot to use the collected intelligence of several geniuses from throughout history to turn Lakertya into a Time Manipulator, allowing her to shape the process of human evolution. However, the Rani is unable to bend the Doctor's mind to her will, and he, Mel, and the Lakertyans and Tetraps are able to bring the Rani to justice, with the Tetraps taking her into custody.

O'Mara's final appearance as the Rani would come in the 30th-anniversary special "Dimensions In Time" in 1993, as the Time Lady escaped Tetrap imprisonment and began collecting an intergalactic menagerie that would once more allow her to experiment with evolution. As she set her sights on acquiring a human, she also embarked on a quest to make sure the Doctor couldn't stop her. Imprisoning his first two incarnations and setting a collection of foes on the other Doctors trapped in a time loop, the combined efforts of the Time Lord and his companions left the Rani tumbling into a Time Tunnel.

"Dimensions In Time" also serves as a crossover between Doctor Who and the popular British soap opera EastEnders, that once starred later Rani actor Dobson.

The Second Rani In Doctor Who Explained

Audio Dramas Introduced The Mara's Second Incarnation

While she escaped the Time Tunnel, the Rani would suffer an injury that would force her to regenerate into her second incarnation, played by Siobhan Redmond within Big Finish's audio drama range. Within her misadventures, the Rani attempted to use the students of the College of Advanced Galactic Education, only for an earlier version of the Sixth Doctor to put a stop to her plans. While she was incarcerated for 97 years, she rose through the ranks to become the governor of Teccoraura Penitentiary and momentarily returned to Miasimia Gora to see the aftermath of her experiment.

In 2021, Big Finish writer Nicholas Briggs revealed that the Rani had not appeared in recent years due to it being difficult to acquire permission to use the character from creators Pip and Jane Baker's estates following their deaths.

However, as the Last Great Time War saw the Time Lords of Gallifrey resort to any strategy necessary to defeat the Daleks, the High Council was willing to bring any renegade Time Lords home to aid their efforts, including the Master. However, with the planet seemingly destroyed in the final days of the conflict, the Doctor assumed his old friend-turned-foe was among the casualties. Even after the planet emerged from its place in a parallel pocket universe, the Rani was not among the survivors.

How The Rani Is Connected To The Mystery Of Mrs. Flood

Flood Has Been Playing The Long Game With The Doctor

However, on December 24th, 2023, Ruby Sunday (Millie Gibson) was met by her neighbor, the seemingly ordinary Mrs. Flood, a woman who had become close friends with her family during their stay in their London flat. Eccentric but seemingly kindly, Flood complained about the sudden arrival of a police box that blocked the pavement. The following day, however, she would watch Ruby step into the TARDIS, wishing her well on her new adventures with the Doctor, knowing very well what she was in store for.

While Mrs. Flood remained a consistent help to the Sunday family, Cherry Sunday (Angela Wynter) would witness a darker side to her as Ruby and Carla (Michelle Greenidge) are summoned to UNIT HQ. As Sutekh's (Michelle Wolfe) sandstorm swept across the Earth, Mrs. Flood stated her true goal was to tear down creation itself, lamenting that the wrath of the God of Death could end her plans before they even began. However, as the Doctor vanquished Sutekh, she ed Cherry in celebrating their revival, even if she knew that the Doctor would be facing worse, hinting at her identity.

As such, Doctor Who season 15 has seen Mrs. Flood step up her meddling, posing as Belinda's neighbor and a prison governor once more to recruit Conrad (Jonah Hauer-King) while following the TARDIS team on their travels. With the Earth set to be destroyed on May 24th, 2025, and the Doctor and Belinda caught in the blast, both Mrs. Flood and the Rani's newly bigenerated incarnation are seemingly set to continue their devastating experiments using the populace of Earth. Should the Doctor survive, a terrifying reunion with an old friend awaits in Doctor Who's season 15 finale.