Went more specific than usual, since they're entirely optional...
Racking Up the Miles, eg. lots of travel involved, or locations are scattered nationwide. Maybe it's a road trip. Maybe they have to catch a lot of flights to get to each scenario. Could be a cruise. Maybe they have to hurry up and wait for their connections and fight off boredom and the feeling that they're wasting time while the threat is getting worse. Call their Bonds, make excuses, call their Handler, make excuses...
Everything Gets Worse, aka. Descent Into Hell. The problem is growing. The Agents can see its symptoms worsening around them. Things are falling apart. Each scenario is more desperate than the last.
Slaughter - ie. Agents or the opposition make a whole lot of kills, personally. Not a big explosion or a gas leak or some other mass-casualty events. Killing, lots of it. Maybe a serial killer, mass-shooter, armed robbery gone wrong, a raid where everyone just starts blasting, a big firefight, unnatural entity attack on a crowded location, or some other cause.