So my son, Finn, is a SERIOUS Lego fan. From about age 3 he massively got into 'little lego' (as opposed to 'big lego' duplo) and in particular Ninjago. Now if you don't know what Ninjago is, it's a lego theme based around four young ninjas, Kai, Jay, Cole and Zane who are all trying to combat the evil Lord Garmadon and his skeleton army. Serious stuff.