The digital special, The Inventors, is an extra stand-alone story which features Andy and Dennis who've found it hard to let go since losing their mum in the Great Storm of 1987. Now with their dad dead too, Dennis reckons it's time to sell their parents' flat, but Andy has a better idea: an invention that might just save the day.
The episode was released on 2014-02-12 at the dedicated website www.insideno9extra.co.uk