London-born Freema had only made a handful of appearances on TV, in soaps such as Crossroads and The Bill, before being picked to replace Billie Piper as Doctor Who's assistant. Although thrilled to land the role, Freema had to keep mum about the news to begin with. "I've been keeping this secret from my friends for months - it's been driving me mad!" she said at the time. "Auditioning with David (Tennant) in secret down in Cardiff was unbelievable, but I never in my wildest dreams thought I'd actually become the new companion."