Thriller

"You were injected with a radioactive substance … it may set off a radiation detection alarm …"

This quote is actually excerpted from a little card that hospitals now give to patients after a test or exam that involves the administration of a nuclear medicine -- for the patients to keep handy in case they accidentally set off an alarm while trying to board certain types of public transportation in the subsequent couple of days.

But taken out of this context, the quote prompts story ideas more along the lines of a thriller ...