Complete the alien commander's confident report to the mothership.

Don't worry, Supreme Leader! By 2050, we _____ the Earthlings' secret recipe for chocolate chip cookies.

The correct answer is will have stolen.

The Future Perfect (will have + past participle) is used here because the action (stealing the recipe) will be completely finished before the future deadline of 2050. Using "will steal" doesn't emphasize the completion of the action by that specific time.