When fish rain from the sky above Ealing, a clue from Mr Smith leads Sarah Jane, Clyde, Rani and Sky to a recently-unearthed totem pole on display at a local museum. While messing about with the exhibit, Clyde gets a livid splinter. He thinks nothing of it until the next day, when suddenly everyone turns against him: Sarah Jane orders him out of her house, Rani says she hates him, and even his mum wants nothing to do with him. Only Sky seems immune, but while she attempts to get to the bottom of the strange sequence of events, Clyde tries to eke out a new life for himself on the streets of London.

While attending the Gallifrey One: 20 To Life convention in Los Angeles in February 2009, Phil Ford, the lead writer for The Sarah Jane Adventures, took the opportunity to meet with executive producer Russell T Davies, who had recently relocated to California. During lunch, the two conceived a story idea which would place the spotlight firmly on Clyde Langer, as both men agreed that actor Daniel Anthony deserved the opportunity to tackle a more mature, complex narrative. Davies suggested the mystical means by which Clyde would find himself living on the streets of London, and Ford then developed these concepts into The Curse Of Clyde Langer. This would become Ford's second contribution to the fifth season of The Sarah Jane Adventures, following immediately on the heels of the year's initial serial, Sky.

Director Ashley Way was assigned to both Sky and The Curse Of Clyde Langer as the fourth recording block for the 2010-11 episodes. The Clyde-focussed tale provided the opportunity to bring back two actors who had not been seen since the second season in 2008: Jocelyn Jee Esien as Clyde's mother, Carla, and Elijah Baker as his schoolmate, Steve Wallace. (During the production of The Curse Of Clyde Langer, Esien would film a scene to be inserted into the fourth-season adventure The Empty Planet, which was found to be running short.) To play the new character of Dr Maddigan, Way cast Sara Houghton, who had previously appeared in programmes such as Trust and Holby City. Houghton's father, Don Houghton, had written the Doctor Who stories Inferno (1970) and The Mind Of Evil (1971), while her mother, Pik Sen Lim, had appeared in the latter as Captain Chin Lee.

Sara Houghton (Dr Maddigan) was the daughter of Doctor Who writer Don Houghton and The Mind Of Evil actress Pik Sen Lim

The first three days of recording on The Curse Of Clyde Langer, from June 22nd to 24th, 2010, were spent on the attic set at Upper Boat Studios. On the 25th, Ebeneser Chapel in Cardiff served as Steven's Point, the soup kitchen seen in the serial; some filming also took place nearby on Charles Street. June 28th dealt with the scenes of Clyde being chased by his schoolmates, beginning at Grange Gardens in Cardiff, and continuing to an alley off Llanmaes Street, Hope Street, School Street and finally the premises of PI Underwood and Son, which also provided the area under the railway arches. The 29th was another busy day in Cardiff, starting with material outside the Museum of Culture, actually the Old Library. Cast and crew then moved to St John's Church, outside of which Clyde tried to use the automated teller, and later he and Ellie panhandled. Finally, Ellie finding Clyde was taped on Crockherbtown Lane.

The interior of the Museum of Culture was actually the Coal Exchange in Cardiff, where recording took place on June 30th. On July 1st, a house on St Asaph Close in Cardiff posed as the Langer residence; this was a different venue than the one which had been used in The Mark Of The Berserker. Work there concluded on the 2nd, after which Way's team moved to Cardiff High School for scenes at Park Vale Comprehensive. A sequence in Sarah Jane's living room was filmed at Clinton Road in Penarth on July 7th, and a variety of inserts were taped at Upper Boat on the 11th. July 12th was another day spent at multiple Cardiff locations. The area where the homeless were living rough was Taffs Mead Embankment. Then various scenes were recorded on Charles Street, most notably Clyde learning of Ellie's departure. More Bannerman Road material was taped at Clinton Road on July 20th, leaving just some pick-up shots to be completed the next day on Hadfield Road in Cardiff.

Post-production altered Clyde's opening narration, incorporating a new line making reference to Sky. A significant edit involved the sequence of Clyde and Ellie panhandling in episode two. In the excised material, Rani emerged from the nearby supermarket and tossed Ellie some coins without noticing her companion. She and Haresh then drove off while Clyde told Ellie that Rani was no longer somebody he knew. In fact, The Curse Of Clyde Langer wound up being the final serial to feature Ace Bhatti as Haresh, due to the unexpected death of Elisabeth Sladen in April 2011. As it turned out, his involvement in further episodes may have been in doubt regardless, as a result of his being cast in a regular role on the soap opera EastEnders. Bhatti's other subsequent appearances have included episodes of Jekyll & Hyde, Beowulf: Return To The Shieldlands and DCI Banks.

• Doctor Who News.
• Doctor Who Magazine Special Edition #32, Autumn 2012, “Episodes 5.3/5.4: The Curse Of Clyde Langer” by Andrew Pixley, Panini UK Ltd.