Detention children
From Tardis Wiki, the free Doctor Who reference
The Detention Children were two human children who lived in Ealing in 2009. They were in Mr Cunningham's detention at Park Vale Comprehensive School for bullying Jacob West. He retaliated by using a Berserker Pendant to destroy their vocal abilities. They later regained them when Jacob abandoned the Pendant. (SJA: The Mark of the Berserker)