Curse of the evil custard

"When Dr Sinister hatches his latest plan to take over the world, and creates evil custard that turns children into deadly blob monsters, what better place to try it out than an unsuspecting school? Little does Dr Sinister realise that Mighty High is a school for superheroes -- they are all acting ordinary to pass the school inspection! Can Stan, Minnie, Miles and, of course, Pudding the Wonder Dog come up with an anti-custard-dote in time?"--Publisher's website.