The whole plot of NIS is in this week's TV Quick:
When The Doctor takes Clara’s charges Artie and Angie to the galaxy’s greatest theme park, not only is it shut and there’s no ice cream, it’s teeming with murderous Cybermen!
The derelict Hedgewick’s World Of Wonder is now the home of a shabby showman, a chess genius dwarf called Porridge-played by Life’s Too Short’s Warwick Davis-and a rabble of soldiers led by Captain (Tamzin Outhwaite).
They’ve all been twiddling their thumbs since annihilating the Cybermen in a bitter war-so they’re understandably stunned when the metal menaces storm in, kidnapping Artie and Angie!
It turns out the Cybermen weren’t wiped out as everyone thought. They’ve been using children who went missing from the theme park as handy spare parts and building a vast army.
As the metallic militia prepares to attack, Clara barricades herself in ‘Comical Castle’ with the soldiers and just one gun to repel the invading hordes while, across the park, The Doctor has his own problems. The Cybermen are now so advanced, they can get into his head.
So when he challenges the cyborgs to a chess battle for control of his mind, he’s in for the game of his life.
A win and the children go free.Lose and the Cybermen gain all knowledge of time travel, The Time Lords and everthing else. No pressure then…..