Olaf and Hannah Stein are the cleverest people in the world. They have developed the MI9 computer firewall and no one else in the world can crack it. Due to their brain power they are in high demand. The spies are sent to escort them to a conference and ensure their safe arrival, but something goes terribly wrong - the Steins are kidnapped right under the spies' noses. But not all of the Steins have been kidnapped - their baby, Grace, is left behind.

Back at St Hope's, Mrs King gives the class computerized infant simulators as an exercise in how to look after children. They look like real babies, sleep like real babies and need feeding just like real babies. This allows the spies to smuggle Grace into St Hope's without being noticed. Carrie and Rose are less than happy to be babysitting Grace, but Oscar is over the moon. Grace is the baby sister he never had and he loves it. If only he could play with her all day.

Unfortunately, the MI9 firewall is under attack, and the spies realise that it must be the Steins. Whoever has kidnapped them is using their brainpower to crack the MI9 database. Oscar is convinced that Grace is trying to tell him something. Why is she craving ice cream? Can the spies communicate with Grace and find her parents in time? Show less