sleeper cells
Definition
A secret group of terrorists, spies, or saboteurs who infiltrate a target country or organization and live unassumingly for years, remaining dormant until activated to carry out an attack or mission.
In a broader or figurative sense, any hidden, inactive group or element that suddenly springs into action, often with disruptive intent.
Examples
The thriller's plot hinged on a sleeper cell of baristas who had been perfecting their espresso espionage for decades.
In the quiet suburb, the sleeper cells blended seamlessly, mistaking block parties for briefings and soccer games for stakeouts.
After hibernating through three Netflix binges, my motivation emerged like a sleeper cell ready to tackle the laundry pile.
Intelligence reports warned of sleeper cells in the boardroom, disguised as overly enthusiastic interns with suspiciously good PowerPoint skills.