Tula was the daughter of Kal Chenka and his wife and sister to Liv. Whilst Tula believed that Liv was the favourite child, Liv always felt that Tula was and later found it impossible to live up to her. Tula greatly looked up to her father, calling him her hero. (AUDIO: Escape from Kaldor)
Career at the Company
Tula began a career at the Kaldor City Company. Seeking to prove herself, she rarely visited her family and missed a number of her father's, mother's and sister's birthdays. Eventually, she learnt that her father did not approve of her work and chose not to return home nor call, incorrectly believing that he hated robots.
Due to her dedication to her career, she rarely visited her family and failed to visit her father after he fell ill. At the time that he died, she was away from Kaldor on Company business. Although she paid the expenses, she did not attend the funeral, causing friction between herself and Liv, and they stopped speaking to each other. Whilst Liv believed that Tula had forgotten about her father, Tula believed that she had said goodbye to her father in her own way. (AUDIO: Escape from Kaldor) She also paid for a state-of-the-art headstone. (AUDIO: The Robots of Life)
Tula became an overtech with the Company and offered her voice to the new generation of Super-Vocs, (AUDIO: Escape from Kaldor) including ones built for psychological counselling. (AUDIO: The Robots of Life) She built and programmed robots and believed that she understood them and was also aware of their use to "purify" the complex of sand rats. She was familiar with the redacted incident files and read her sister's debrief of the events aboard the Lorelei. (AUDIO: Escape from Kaldor)
Tula had a brief, passionate relationship with Captain Garlon Rosh, which she called off due to it being unprofessional. However, the two still harboured feelings for one another, with Tula describing it as a "wonderful mistake". (AUDIO: The Robots of War)
The Eighth Doctor visited Tula, who gave him a demonstration of SV111 believing that he was a client. She soon learnt that he was a friend of Liv's and was intending to reunite the sisters. Initially suspicious of him after the robots began attacking, she learnt his identity as the Doctor that she had read about in the files concerning Storm Mine 4 and the Lorelei and took him to Galla Posca.
Having the voice of the Super-Vocs and technology able to pass herself off as one, she sneaked into the complex to free the humans there, bumping into Liv, Helen Sinclair and Kit Laver on the way. Tula and Liv discussed their father and came to an understanding, with Tula finally apologising for never having returned home. After the robots were restored by the Doctor and Lina Hadway, Tula believed that the matter should not be covered up. Posca, however, disagreed.
Tula offered Lina a job at the Company but was refused. She then asked SV23 to track down Liv using the Kaldor Bionetwork, but it was unable to find her as she was in the TARDIS. (AUDIO: Escape from Kaldor) Liv joined her shortly after. (AUDIO: The Robots of Life)
Year with Liv
A week after Liv moved in with Tula, the two visited their father's grave. After Liv was denied a job at Kaldor City Hospital, Tula pulled some strings to have the need for a Ward Hygiene Certificate removed, leading to her being hired. She got on the wrong side of her new boss, Overseer Skellen, after Liv convinced her to look into the Company's recording of dead people's memories using his access code. Whilst he did not want to fire her, he put a permanent warning for misconduct on her record. However, without Tula's knowledge, Liv blackmailed Skellen with a recording of SV57 displaying sentience, causing him to remove the warning. (AUDIO: The Robots of Life)
Tula invited Liv to help her with a clairvoyance test, after which she showed her the Vissey. Once Vissey's disturbing behaviour came to light, it was decided that she would be put in stasis. However, Professor Til Rork helped her escape, after which Rork, Tula and Liv tracked her down to the Kaldor Company Fusion Plant where Rork sedated her. The project was ruled untenable but Tula had faith that work on artificial intelligence would resume shortly after with additional systems and checks, something that Liv disagreed strongly with. (AUDIO: The Sentient)
Tula was concerned after Roboanalyst Volar Crick returned to work so soon after his wife's death. Investigating the matter, she and Liv found that Skellen had sent him a Super-Voc, SV39, who adapted itself to become Jasdar Crick. Upon making Skellen aware of this, Crick was taken away by a Mental Health Tech. Liv told Tula that she had a feeling that things were changing on Kaldor, noting their recent experiences with SV57, Vissey and SV39. (AUDIO: Love Me Not)
Tula had something of an ego, which she believed was inevitable for one involved with the creation of artificial intelligence. She left her family in order to prove herself to her father, who she had always considered to be her hero, and was upset when she learnt that he did not approve of her work.