Seven-year-old Tim Templeton has always had an overactive imagination--and for the past seven years--life has been all peaches and cream, getting all the love and affection from his caring parents. However, after the arrival of Boss Baby, an unexpected new brother dressed in a black suit complete with a tie and a briefcase, little by little, Tim realises that the cute newcomer has taken over the whole house, robbing him of his happiness. But, soon, Tim and the new boss in a diaper will need to put differences aside and join forces, as a sneaky scheme involving the head of Puppy Co. threatens to tilt the balance of power towards their insidiously adorable furry antagonists. Now, the next pet convention is only in two days. So, brothers, hurry up.