Jenna Coleman's character Clara took on the role of the Doctor in the latest episode of BBC show 'Doctor Who' entitled 'Flatline' - but how does that leave the real Doctor feeling about his companion?

Peter Capaldi in Doctor Who series 8, episode 9: Flatline
The Doctor's trapped in the TARDIS in 'Flatline'

The tension between the Doctor and Clara has been at a peak since, well, since he regenerated from the happy-go-lucky Matt Smith facade to the grumpy and sour-tempered image of Peter Capaldi. But Saturday's episode (October 18th 2014), marked a turning point as Clara was forced to think like a Timelord when they landed in a particularly dangerous situation in Bristol. The TARDIS appeared to be inexplicably shrinking from the exterior, which ultimately left the Doctor stuck inside and Clara on the outside attempting to find and fix the problem.

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The issue, it seemed, was that a race of destructive 2D creatures were invading the city, feeding off the third dimension of their victims in a bid to become more mobile. Clara claimed to a young graffiti artist on community service that she was the Doctor, realising that she had the sonic screwdriver and that it was her job to investigate the aliens behind the missing people while the real Doctor could only look on having hacked into her optic nerve.

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It was clear that the Doctor was becoming increasingly frustrated with her lies, which she usually reserves for her boyfriend and colleague Danny. When the creatures eventually became virtually 3D  in the shapes of the zombified missing people and Clara lost contact with the Doctor, she found a way to harness their power to give energy back to the TARDIS, thus returning it to normal size and allowing the Doctor to banish the creatures. Clara was thrilled with herself for saving the day, remarking firmly to her usually stubbornly unfeeling friend that 'I was the Doctor and I was good'. The Doctor responded quite simply: 'You were an exceptional Doctor, Clara. Goodness had nothing to do with it.'

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It was a line that left a strange feeling in the hearts of viewers; is this more evidence of the relationship between the Doctor and Clara falling apart, or is everyone's favourite time traveller feeling distinctly more sorry for himself than usual? If one thing's for certain it's that things are going to come to a particularly explosive climax over the course of the final three episodes of series eight. Which is just as well because the mysterious Missy in her 'heavenly' abode finally has her eye on the Doctor's 'Impossible Girl'.

Episode 10, 'In the Forest of the Night', will be broadcast on BBC1 on October 25th 2014.