Maria wakes up one morning to discover, much to her horror, that she is the only one who remembers Sarah Jane Smith. Clyde has never heard of her, Luke is nowhere to be found, and a woman named Andrea Yates now lives in Sarah Jane's house. To make matters worse, an enormous meteor that Mr Smith was going to deflect is now on a collision course with Earth. Maria becomes convinced that Andrea has something to do with her vanished friend. But as she begins to uncover a tragedy in the distant past that involves both women, will Maria become the next person erased from history by the malevolent Trickster?

Gareth Roberts had recently completed Revenge Of The Slitheen, the initial story for the first season of The Sarah Jane Adventures, when executive producer Russell T Davies asked him to write another serial to air later in the year. A key requirement was that it should be structured in such a way that it would afford series star Elisabeth Sladen some time off in the middle of the production schedule. Furthermore, Davies requested the return of the Graske, a monster which Roberts had developed for his 2005 interactive Doctor Who game Attack Of The Graske. Its storyline had revolved around the alien Graske's plot to kidnap humans and replace them with duplicates.

Roberts was keen to develop a narrative with more emotional heft than his prior contributions to The Sarah Jane Adventures. To this end, he seized upon an idea he had devised some time before, in which time was changed such that Sarah Jane now died in childhood. This became Whatever Happened To Sarah Jane?, a title inspired by the 1962 Bette Davis/Joan Crawford thriller What Ever Happened To Baby Jane?. The story would be made on its own as Block Two of the season's production schedule, although it was planned that it would be broadcast fourth, between Warriors Of Kudlak and The Lost Boy, the two serials which would comprise Block Three.

In 1994, Jane Asher (Andrea Yates) portrayed the Doctor's granddaughter, Susan Foreman, in a radio satire

Assigned to direct Whatever Happened To Sarah Jane? was Graeme Harper, a Doctor Who veteran whose involvement with the programme had begun in the Sixties. Most recently, he had made 2007's 42 and Utopia. Cast as the adult version of Sarah Jane's childhood friend, Andrea Yates, was Jane Asher. Her career dated back to the Fifties, and included films such as The Masque Of The Red Death and Alfie, as well as television programmes like Brideshead Revisited, Wish Me Luck and Crossroads. In the 1994 radio satire Whatever Happened To... Susan?, Asher had portrayed the Doctor's granddaughter, Susan Foreman -- the role originated by Carole Ann Ford during Doctor Who's very first season. Jessica Ashworth won the role of the young Sarah Jane; her resume included appearances in The Bill and Genie In The House. Meanwhile, former sculptor Paul Marc Davis appeared beneath prosthetics as the Trickster. He had made his professional acting debut in the 2001 film Harry Potter and The Philosopher's Stone, and was known to the Doctor Who team from his work as the Chieftain of the monstrous Futurekind in Utopia, which had been recorded in January and February.

The first day of recording for Block Two was May 24th, 2007, when work at the programme's regular studio facilities in Upper Boat took place on the sets for the Jacksons' junk room and Sarah Jane's attic. The same day, the news items were taped at BBC Broadcasting House in Cardiff. Filming on the 25th began at the Dinas Powys Skatepark, located within Parc Bryn-y-Don in Dinas Powys. Cast and crew then moved to Penarth, where Maria was captured by the Graske on Archer Place before Clinton Road posed as Bannerman Road.

Clinton Road remained the focus after the weekend, on May 28th and 29th. Then it was back to Upper Boat from May 30th to June 1st, for sequences in Maria's bedroom and Sarah Jane's attic. June 1st wrapped up with a night shoot on Clinton Road, and work resumed there following another break for the weekend, on the 4th and 5th. Material at Westport Pier was recorded on June 6th at Penarth Pier, while the Limbo set at Upper Boat was in use on the 7th. June 8th was spent in Cardiff, beginning at Park Place for Clyde's phone call from Maria, plus Maria and Alan leaving the Roseborough Research Library. The Science Library at Cardiff University then served as the Roseborough's interior, before Maria's escape from the Graske took place at Cardiff Heliport. This left only some pick-up shots of Mr Smith, which were recorded at Upper Boat on June 14th.

The first episode of Whatever Happened To Sarah Jane? aired on CBBC on October 29th. To date, The Sarah Jane Adventures had performed well on both CBBC and BBC One, but it really hit its stride the following week, on November 5th, when Episode Two was watched by 633,000 viewers. This was the largest audience for the digital channel since its inception on February 11th, 2002.

• Doctor Who Magazine Special Edition #23, 24th December 2009, “Episodes 1.7/1.8: Whatever Happened To Sarah Jane?” by Andrew Pixley, Panini Publishing Ltd.