into the belly of the beast

cliché Into the worst, most central area or part of something deeply unpleasant or malicious. The undercover agent, posing as a drug manufacturer, found himself venturing into the belly of the beast after being invited to meet the city's crime lord. As a business person, she spent her entire career railing against a government she claims is corrupt. Now she's heading into the belly of the beast as a newly elected US senator. You've discovered who's behind the sex trafficking operation? Then you've moved into the belly of the beast then, my friend.