Rani is feeling alienated from Sarah Jane, Luke and Clyde. When her old friend Sam asks her to come back home to Danemouth to investigate a mystery, she's quick to accept. Stories of disappearances at a derelict amusement park lead Rani to an alien girl named Eve, who crashlanded on Earth and was hidden in the park by its caretaker, Harry. But Eve and her damaged vessel possess devastating powers that transcend time and space, and when Sarah Jane and her companions come looking for Rani, their actions may put their own futures at risk...

As originally planned, the third season of The Sarah Jane Adventures was to climax with a story which guest-starred David Tennant as the Tenth Doctor. Correspondingly, the year's fifth serial was designed to help pave the way for the finale -- both by incorporating a prophetic element which would hint at the events to come, and by bringing back K·9 for a more substantial role in the programme. To date, the robot dog had only made brief appearances in 2007's Invasion Of The Bane and The Lost Boy, but an agreement how now been reached with co-creator Bob Baker which would allow K·9 to feature more prominently.

The rough sketch developed for the season's penultimate story was that it would involve an alien who was stranded on Earth and was trapped at an amusement park. The alien would possess a variety of psychic powers, some of them temporal in nature. K·9 would make a surprise appearance at the end of the story to help restore the alien's spaceship. Originally, it was hoped that this adventure would be developed by a writer new to The Sarah Jane Adventures but, in November 2008, it was reassigned to Joseph Lidster, who had contributed The Mark Of The Berserker to the show's second season.

Originally, the alien girl was captured by slimy businessman Mark Grantham from Warriors Of Kudlak

Lidster initially saw the story as an opportunity to reflect on the consequences of Sarah Jane's actions. As such, the narrative was tied to the events of 2007's Whatever Happened To Sarah Jane?, with the meteor which had been deflected during its climactic moments now revealed to have caused an alien girl to crashland on Earth. She was captured by slimy businessman Mark Grantham -- from another 2007 serial, Warriors Of Kudlak -- who now ran the Galaxy World park with his assistant, Ms Brown. Rani travelled to Galaxy World with two classmates: Steve Wallace and Jacob, who had respectively appeared in The Day Of The Clown and The Mark Of The Berserker during the show's 2008 season. Grantham wanted to take advantage of the girl's prophetic abilities, but it would transpire that Ms Brown was actually her mother, and was trying to nurture her destructive powers for the benefit of an alien army.

As work continued, Grantham, Ms Brown and Steve -- who briefly acquired a girlfriend named Katie -- were all dropped from the storyline. The alien girl became known as Eve, and the theme park was rebranded as FutureWorld and located in the fictional town of Danemouth, a name drawn from the 1942 Agatha Christie novel The Body In The Library. It would now be explained that Jacob had been relocated to a children's home in Danemouth following the events of The Mark Of The Berserker, and he summoned Rani for help to investigate a string of disappearances. At the start of December, a new villain was added in the form of a man who claimed to be the Master, the Doctor's Time Lord arch-nemesis. He was apparently planning to use Eve as the first soldier in a time-sensitive army, while punishing the Doctor by torturing Sarah Jane and her friends. However, it would ultimately be revealed that this was not the Master, but rather a man whom Eve had brainwashed into believing himself to be the Master in order to lure the Bannerman Road gang to FutureWorld.

By early 2009, the ersatz Master was removed from the narrative, and his role was largely taken by the more sympathetic figure of the park caretaker, Harry. Lidster began to emphasise Rani's role, viewing his new story -- eventually called The Mad Woman In The Attic -- as a companion piece to the Clyde-focussed The Mark Of The Berserker. Thematically, the scripts now dealt with the difficult progression to adulthood and independence.

Perry Millward was unavailable to reprise his role as Jacob from The Mark Of The Berserker

Meanwhile, it became known that Tennant would have to record his appearance in The Sarah Jane Adventures much earlier than originally planned. That story, The Wedding Of Sarah Jane Smith, was therefore repositioned as the third serial in both the production and broadcast schedules. This, in turn, meant that The Mad Woman In The Attic would also have to brought forward, becoming the year's second adventure. Unfortunately, actor Perry Millward would no longer be available to reprise his role as Jacob so Lidster introduced a new character, Sam, with the idea being that Danemouth was Rani's hometown before the Chandras moved to Bannerman Road. The writer was also asked to minimise Luke's participation in the story, since Knight would be heavily involved with his GCSE exams during production.

For its third season, budgetary constraints had imposed a new recording schedule on The Sarah Jane Adventures. The six serials would each form a filming block of their own, alternating between two directors. For stories two, four and six, the director would be Alice Troughton, who had made Revenge Of The Slitheen and Eye Of The Gorgon during 2007. In the interim, Troughton had directed The Doctor's Daughter and Midnight for Doctor Who's 2008 season. Cast as Harry was Elisabeth Sladen's husband, Brian Miller, who had previously appeared in the 1983 Doctor Who story Snakedance; he had also provided Dalek voices on multiple occasions. Playing Rani at age sixty-five would be Souad Faress, whose extensive resume included episodes of Blake's 7, Coronation Street and No Angels, as well as films such as My Beautiful Laundrette and the long-running radio soap opera The Archers.

The first three days of production on The Mad Woman In The Attic were spent at the show's regular studio home in Upper Boat. May 5th involved work on the attic set -- redressed for its 2059 appearance -- which continued to the next day. Recording on the 6th then moved on to Rani's bedroom. Filming on May 7th dealt with material which involved the Haunted Mine ride and Luke's future graduation, as well as shots of the Ship avatar. On May 8th, Harry's office was set up at an industrial unit on the Treforest Industrial Estate in Pontypridd. After the weekend, May 11th saw the Kymin -- a community centre in Penarth -- pose as St Andrew's Children's Home. Cast and crew then returned to Upper Boat, for sequences in the modern-day attic on the 12th and aboard the spaceship on the 13th.

The major location for The Mad Woman In The Attic was the Barry Island Pleasure Park. The attraction, which had been founded at Barry in 1897 as the New Evesham Pleasure Park, was closed for the season and offered an appropriate beach area; filming there took place on May 14th, 18th and 20th. In between, on the 19th, the Haunted Mine storeroom was actually part of Jacob's Antique Centre in Cardiff. Establishing shots of 13 Bannerman Road in both the present day and 2059 were captured at Clinton Road in Penarth on May 21st, followed by inserts involving K·9 at Upper Boat on the 22nd.

• Doctor Who Magazine Special Edition #28, 13th July 2011, “Episodes 3.3/3.4: The Mad Woman In The Attic” by Andrew Pixley, Panini Publishing Ltd.