During the episode "The Almost People", a clone of the Eleventh Doctor speaks the phrase while reliving the memories of all his predecessors. He goes on to conflate it with his regeneration-spanning love of jelly babies, remarking that they need to "reverse the jelly baby of the neutron flow". In "The Day of the Doctor", the Eleventh Doctor invokes the phrase when confronting a time portal with the Tenth Doctor, suggesting that they both "reverse the polarity" with their sonic screwdrivers (which merely neutralizes each other’s efforts). In "The Girl Who Died", the Twelfth Doctor tells Clara Oswald he is "Reversing the polarity of the neutron flow", followed by "I bet that means something. It sounds great." Clara herself uses the phrase, saying she "reversed the polarity" of a mind-wiping device to prevent the Doctor from erasing her memories of him from her mind ("Hell Bent"). In "It Takes You Away", Yasmin Khan suggests that the Thirteenth Doctor reverse the polarity on the sonic screwdriver in order to (successfully) open a locked inter-universe portal.