Suddenly, rapidly, short, fast, on a sudden, swiftly, right, surprisingly, hastily, speedily, readily, impulsively, right off, impetuously, rashly, posthaste, full tilt, unexpectedly, quickly, immediately, promptly, all of a sudden, instantly, quick, instantaneously, incontinently, straightaway, directly, swift, right away, recklessly, pronto, and snappily.