Sarah Jane uncovers a new scheme by the Slitheen to destroy the Earth, but the villains are stopped by the Blathereen, members of another family on Raxacoricofallapatorius. The Blathereen profess nothing but goodwill towards the human race, and offer Sarah Jane the gift of Rakweed, a hardy and nutritious plant which can grow in even the most hostile of environments. Although Sarah Jane does not entirely trust the Blathereen, she decides to take a chance and accept the Rakweed -- little realising that the Blathereen have their own sinister designs on Earth.

Alongside Brian Dooley -- the writer who originally developed Mona Lisa's Revenge -- the other new contributor to the third season of The Sarah Jane Adventures was Rupert Laight. Laight had worked with Gareth Roberts, one of the programme's regular writers, as a storyliner on Emmerdale, and he had contributed 2002's Ghost Town to the first season of Sarah Jane Smith audio adventures from Big Finish Productions. More recently, he had novelised two stories from the first season of The Sarah Jane Adventures for Penguin Characters Books. Laight was invited to write for the programme itself in late 2007, when the production team was given the green light to plan for not one but two seasons of the show.

Laight was aware that his episodes were destined for the 2009 season, allowing for extensive development. As a starting point, he was asked to introduce the Blathereen from the planet Raxacoricofallapatorius. This was also the homeworld of the Slitheen, who had battled Sarah Jane in the serials which bookended the first season: Revenge Of The Slitheen and The Lost Boy. The Blathereen themselves had already appeared as villains in the 2005 Doctor Who novel The Monsters Inside, written by Stephen Cole and published by BBC Books. Laight's story, which was originally functionally designated “Blathereen”, became “Gift Of The Blathereen”.

It was intended that The Gift would feature an appearance by Noel Clarke, reprising his Doctor Who role as Mickey Smith

In addition to both sets of Raxacoricofallapatorians, it was intended that Laight's serial would feature an appearance by Noel Clarke, reprising his role as Mickey Smith, the Doctor's sometime companion, who had appeared during the 2005 and 2006 seasons of Doctor Who. Mickey returned to Earth following a spell in a parallel universe in the 2008 Doctor Who season finale, The Stolen Earth / Journey's End, and would now be allied with the Unified Intelligence Taskforce (UNIT). As originally envisaged, Mickey helped Sarah Jane and her friends track the Slitheen at the start of the story, before becoming enmeshed in the struggle against the Blathereen.

In early versions of “Gift Of The Blathereen”, the titular “gift” -- called Yorrum grass at this point, rather than Rakweed -- was already being grown in the Sahara desert, from where it rapidly spread to infect various parts of the globe, including England. Sarah Jane was able to track the Slitheen, who were being held captive by the Blathereen. The Slitheen agreed to help the humans, only to betray them to the Blathereen -- but not before providing enough information about Yorrum grass to enable Mr Smith to synthesise a weedkiller. As “Gift Of The Blathereen” evolved, the involvement of the Slitheen -- who now included Janine Slitheen from Revenge Of The Slitheen -- was reduced, with the weedkiller being created with help from the work of Professor Cowly, whose research centre was now the starting point for the Yorrum grass infestation.

Unfortunately, it eventually became apparent that Noel Clarke would not be available during the production period, so Mickey would have to be dropped from the storyline. In the new version, Cowly and his research centre were eliminated, with the Blathereen offering the Yorrum grass directly to Sarah Jane. The Yorrum grass was now susceptible to a solution made from daffodils, as Rani discovered when she and Clyde escaped to her mother's flower shop. Laight dubbed this draft “The Whispering Grass”, in reference to the song Whispering Grass (Don't Tell The Trees), a 1975 hit for Windsor Davies and Don Estelle. Ultimately, however, the serial would go by a simplified version of the earlier working title: The Gift.

The Wedding Of Sarah Jane Smith became the year's third serial, with The Gift taking its place as the climactic adventure

By now, Laight's story was intended to be fourth in both the production and broadcast schedules for the 2009 season of The Sarah Jane Adventures. This imposed further adjustments: Tommy Knight would have to be excluded from the narrative because filming would coincide with the writing of his GCSE examinations, while Clinton Road in Penarth would not be available to appear as Bannerman Road. However, things changed again when the entire structure of the 2009 season was revised in order to accommodate the schedule of David Tennant, who would be appearing as the Tenth Doctor in The Wedding Of Sarah Jane Smith. It was originally planned to be the season finale, but now became the year's third serial, with The Gift taking its place as the climactic adventure. This meant that Bannerman Road and Luke could both appear -- as could K·9, whose return originally took place after the events of Laight's episodes.

The final form of The Gift now began to take shape, such as the introduction of the Rakweed's vulnerability to sound. All along, one of the biggest difficulties which Laight had faced was identifying an appropriate motive for his story's villains. Earlier drafts had suggested that the Blathereen were genuinely trying to help humanity, but were unaware of what would happen when they unleashed their gift; that only one of the Blathereen was evil, unbeknownst to the other; or that the Blathereen were motivated by the dying ecosystem of Raxacoricofallapatorius and were planning to turn the Earth into a new homeworld. Only at a late stage was it decided that Tree-Lorn-Acre and Leef-Apple-Glyn -- named for JRR Tolkien's 1964 book Tree And Leaf -- were actually products of a Slitheen-Blathereen union.

The Gift was directed by Alice Troughton, who had just completed The Eternity Trap. For a time it was thought that money could be saved by repainting the existing Slitheen costumes to turn them into Blathereen, but new costumes were ultimately constructed. At one point, Laight had envisaged the Blathereen as being a shade of blue, but they were eventually coloured a more distinctive orange. Troughton's first two days of shooting were July 2nd and 3rd, 2009, both of which were split between Clinton Road and the attic set at the show's usual studio home in Upper Boat. Scenes in the attic remained the focus from July 7th to 9th, with the shot of the exploding Blathereen held back until last, due to the amount of time it would take to clean and repair the set. Part of the 9th was also spent at the QED Centre -- located on the Treforest Industrial Estate in Pontypridd -- for the news report from Park Vale Hospital. The 10th was another day spent at Upper Boat, this time for sequences in the Chandra residence.

Since the start of production on The Sarah Jane Adventures, two different schools had been used to represent Park Vale Comprehensive: Hawthorn High School in Pontypridd and Cardiff High School. Both were utilised for The Gift, the former on July 11th and the latter on the 13th and 14th. Scenes in reception and the staff room were taped at Hawthorn High, and those in and around the science lab at Cardiff High. The Blathereen spaceship set at Upper Boat was Troughton's focus on the 15th. This left just the Slitheen confrontation from the start of the story, which was recorded at the Hoover Candy factory in Merthyr Tydfil on July 16th and 17th, wrapping up the year's shooting schedule.

Episode Two of The Gift brought the third season of The Sarah Jane Adventures to a close on November 20th, and marked the first time that the antagonist of the season's opening serial did not return for the finale. In comparison with 2008, the show's ratings had improved considerably during 2009, bolstered by Tennant's mid-season appearance and the new twice-weekly, BBC One-oriented broadcast schedule. The future of The Sarah Jane Adventures seemed assured, and planning was already well under way for not just a fourth season, but also a fifth. However, after a year of relative stability both in front of and behind the camera, 2010 was to bring a period of substantial change...

• Doctor Who Magazine Special Edition #28, 13th July 2011, “Episodes 3.11/3.12: The Gift” by Andrew Pixley, Panini Publishing Ltd.