Four Weddings And A Funeral writer Richard Curtis was told to redraft his Doctor Who episode because the Time Lord talked too much, he has revealed.
Curtis, 51, who wrote classic TV series Blackadder, said he was also told by show producers the beginning was "too slow".
"It was nice being pushed around in the right direction and having a format," he said.
Curtis' episode, which features Vincent van Gogh, will be shown this Saturday.
Speaking after a screening of the episode at BFI Southbank in London, Curtis said he had been given "all sorts of instructions" about the Doctor and his relationship with assistant Amy Pond.
"I remember I was told, when I first handed in my first draft, the doctor talked too much and that I should go back and watch some of the episodes and see that, actually, he was rather efficient in the way that he talked."
Despite initial resistance, Curtis said that, after a read through with Matt Smith, who plays the Doctor, and his co-star Karen Gillan, he "suddenly realised they were right and it was bad - and then I re-wrote it".
In Saturday's episode, Van Gogh is shown taking a shine to Gillan's character.
"I was told very much that Amy's in a peculiar position with reference to the state of her heart," Curtis said.
Also speaking after the screening, Gillan said viewers would need tissues for the finale of the series later this year.
She said it would be "a big climax for Amy and her story that's been building throughout the series".
Filming the scenes had "required a lot of kind of concentration and emotion", she added.