Carla can't believe it, first her best friend Herta moved to Australia and now in the first lesson after the holidays Jole, the new kid in her class, sits next to her and makes embarrassing jokes. This is clearly too much for shy Carla – she becomes invisible and takes on the colour and texture of her surroundings. 

Fortunately, nobody notices. Except Jole, who enthusiastically observes this transformation. Carla herself is horrified! She absolutely wants to be normal! Unfortunately, it doesn’t stop at this one transformation and soon a secret society also becomes aware of Carla's rare quality. “The Cavaliers" want to harness the power of Carla's transformation for themselves. When Herta finds out that Carla has severe chameliosis, she sends her a special pill. Unfortunately Carla’s penguin Mr. Ping swallows it, then develops a sling tongue and won’t stop talking in rhymes.... but this is just one of many problems Carla and Jole have to solve.