Strange lights in the sky draw Sarah Jane, Maria, Luke and Clyde to a radio tracking station. There they find a teenaged girl called Lucy Skinner, whose scientist father is behaving very strangely. Searching the nearby woods, they discover a spaceship piloted by Commander Kaagh, the last survivor of the Sontarans' recent Earth invasion. Kaagh is determined to avenge his people by manipulating the tracking station's technology to crash artifical satellites down onto the world's nuclear reactors, with apocalyptic results. But even as she strives to stop Kaagh, Maria must grapple with the prospect of leaving Bannerman Road forever.

Yasmin Paige had played Maria Jackson since Invasion Of The Bane, the special which launched The Sarah Jane Adventures on New Year's Day 2007. During planning for the show's second year, however, Paige informed the production team that she would be unable to continue in the role, because the recording schedule would conflict with her GCSE examinations. A replacement character, Rani Chandra, was devised but it was noted that Paige would be available to film a final story during June 2008. As such, Maria would be written out in the season's first serial, with Rani then making her debut in the subsequent adventure. As a result, Maria's parents, Alan and Chrissie, would also make their exit from The Sarah Jane Adventures.

The season premiere was amongst three allocated to Phil Ford, who would also be writing Rani's introduction in The Day Of The Clown. Originally, the plan for Maria's last story was that it would feature the Judoon, the intergalactic police force introduced in the 2007 Doctor Who premiere Smith And Jones, in a story called “The Trial Of Sarah Jane Smith”. These events would have been foreshadowed by the final scene of the opening season, with Sarah Jane and her friends noticing that the rain on Bannerman Road was falling upwards -- the same meteorological phenomenon previously witnessed in Smith And Jones. Then, in “The Trial Of Sarah Jane Smith”, Sarah Jane would be captured by the Judoon and placed on a sham trial at which various old enemies would appear to testify against her. She would be defended by Mr Smith, who had gained humanoid form, while her friends were trapped in the attic and tried to figure out how to escape.

The Sontarans had first been seen in 1973's The Time Warrior, which had also introduced Sarah Jane

When “The Trial Of Sarah Jane Smith” was abandoned, the next idea for the opening serial made use of one of Ford's favourite Doctor Who monsters: the Sontarans. They had first been seen in 1973's The Time Warrior which, coincidentally, had also introduced Sarah Jane. Ford had already made reference to the militant aliens in 2007's Eye Of The Gorgon, but he was unaware at the time of plans to bring the Sontarans back in The Sontaran Stratagem / The Poison Sky, a two-part story broadcast during Doctor Who's 2008 season. Since this meant that a variety of props and costumes would now be available, Ford seized on the opportunity to lead off the new season of The Sarah Jane Adventures with a Sontaran narrative, which would tie in with the events of their latest confrontation with the Doctor. Executive producer Russell T Davies gave his approval to the idea, although he was wary of leaning too heavily on plot points from Doctor Who.

Due to the limitations of Paige's availability, Ford's season opener -- eventually called The Last Sontaran -- was scheduled to be made as part of the year's second recording block alongside the fourth serial, The Mark Of The Berserker. The director was Joss Agnew, who had been working regularly on The Story Of Tracy Beaker and Young Dracula. The first recording for The Last Sontaran took place at Castell Coch Woods in Tongwynlais on May 21st, 2008, and consisted of Alan and Chrissie's arrival in the vicinity of the tracking station. The 22nd saw Clinton Road in Penarth once again double for Bannerman Road. On May 23rd, cast and crew were at work on the sets for Sarah Jane's attic and the Tycho station at the programme's regular studio facilities in Upper Boat. The scientific facility's control room was realised on location, at Alpha Steel in Newport, on the 29th and 30th.

More attic material was taped at Upper Boat on June 6th, followed by establishing shots of Bannerman Road at Clinton Road on the 10th. Yasmin Paige's first filming for The Sarah Jane Adventures in eleven months took place on June 11th, initially at Castell Coch Woods and then back at Upper Boat for attic and service tunnel scenes. On the 12th, Agnew's team travelled to the Brackla Bunkers near Bridgend for more tunnel sequences, as well as those at the rear of the Tycho facility. June 13th was scheduled to be spent on Clinton Road, but this work had to be deferred when Paige fell ill. Instead, material in the Jacksons' kitchen was completed at Upper Boat, along with effects and insert shots. Studio work continued on the 15th, on the sets for the Jackson residence, the rec room, and Kaagh's ship.

Agnew's team returned to Alpha Steel on June 16th and 17th, focussing on scenes in the control room and the Operations Systems Building. Exterior shots of the Tycho station were then captured at a Ministry of Defence training area in Caerwent on the 18th. Principal photography on The Last Sontaran concluded with three days -- June 23rd to 25th -- at Hensol Forest near Welsh St Donats for more woodland sequences. This left just the deferred Bannerman Road material, some of which was dropped altogether, while the remainder was completed at Clinton Road on July 18th. This was the last day of work on The Sarah Jane Adventures for Yasmin Paige, as well as for Joseph Millson and Juliet Cowan, who played her parents. However, Paige and Millson had already recorded a further appearance for The Mark Of The Berserker, which would be broadcast as the year's third story.

For its second season, The Sarah Jane Adventures retained the same transmission schedule as for its first year, with episodes making their debut on the CBBC digital channel one week before being repeated on BBC One. As in 2007, the exception was the season premiere -- The Last Sontaran Episode One -- which had its first broadcast on BBC One on September 29th, immediately before Episode Two aired on CBBC. Once again, The Sarah Jane Adventures proved to be a success for both channels, drawing significant audiences to the Monday late afternoon timeslots.

• Doctor Who Magazine Special Edition #23, 24th December 2009, “Episodes 2.1/2.2: The Last Sontaran” by Andrew Pixley, Panini Publishing Ltd.
• Doctor Who Magazine Special Edition #32, Autumn 2012, “Episodes 5.5/5.6: Meet Mr Smith” by Andrew Pixley, Panini UK Ltd.