[5] During one tour of the factory, an alarm is set off when visitor Kelsey Hooper's (Porsha Lawrence Mavour) mobile phone disturbs the Bane Mother.

[5] The Archetype awakes and proceeds to escape with visitor Maria Jackson (Yasmin Paige) and her investigative journalist neighbour, Sarah Jane Smith (Elisabeth Sladen).

[5] Sarah Jane reveals to Luke and Maria that she is a former time traveller, having been a companion of the Doctor (Jon Pertwee and Tom Baker) and lives a dangerous life investigating alien invasions and schemes on Earth.

[6] Luke struggles to adapt to life at school owing to his inability to lie or master humour and his apparent genius-level intellect which sets him apart from his fellow pupils.

[7] He and Maria (who is also new to the school having moved recently to the area) meet and befriend Clyde Langer (Daniel Anthony), whilst Luke makes an enemy of Carl (Anton Thompson McCormick), an intelligent boy who envies his effortless intellectual superiority.

[10] A plot by extra-dimensional villain the Trickster erases both Luke and his mother from history in the story Whatever Happened to Sarah Jane?, although Maria successfully restores it in the second part.

[15] Subsequently, the Doctor Who Series 4 finale features Luke, Sarah Jane, Mr Smith and robot dog K9 witness a Dalek invasion of Earth.

[1][2] Following this, Series 2 of The Sarah Jane Adventures (2008) sees Luke part ways with Maria when she moves to America in The Last Sontaran,[16] and befriend investigative new girl Rani Chandra (Anjli Mohindra) who comes to discover the extraterrestrial activities that he, Clyde and his mother are involved with in The Day of the Clown.

[17] In the Series 2 serial, The Temptation of Sarah Jane Smith, Luke meets his grandparents in a time travel plot set up by the Trickster.

[18] In Series 3's The Mad Woman in the Attic (2009), an alien shows Luke a vision of the future in which he appears to be graduating from university at a young age.

[22] Due to infectious alien spores, Luke becomes sick for the first time and nearly dies, spurring Sarah Jane to take up arms against their enemy.

[23] At the beginning of The Sarah Jane Adventures Series 4 (2010), Luke is written out during the episode The Nightmare Man as the character departs to attend the University of Oxford after having taken his A Levels ahead of schedule,[24] although makes regular cameo appearances episode-to-episode in communicating with his friends and mother via webcam.

"[33] The mini episode Farewell, Sarah Jane, published on the official Doctor Who YouTube channel confirmed Luke's sexuality as he says that he and Sanjay have been married for five years.