Marseille, France: on Monday, heavily armed gangsters opened fire on a police car. Nobody was reported injured, and a response team - 100 special forces police - were dispatched to lock down and search the housing estate, Castellane, where the incident took place. A small cache of weapons, money and drugs is reported to have been found.
According to reports the occupants of the police car were Pierre-Marie Bourniquel, the departmental director of public security, and a police chief. They were inspecting the estate, a known narcotics hub, prior to the arrival of the Prime Minister, who was supposed to congratulate the city on its crime crackdown.
They fell foul of a small group of assailants armed with Kalashnikovs, who were searching the estate for members of a rival gang. One sniper apparently got a little too excited, and started firing at the police car when it showed up.
All of which goes to show just how quickly things can deteriorate, under the right circumstances. I very much doubt that the gangsters wanted to be hit by a special ops unit, 100 members strong. Equally I doubt that Marseille really wanted this kind of black eye just before the Prime Minister's visit.
However it does suggest an interesting possibility for Night's Black Agents: what would happen if, at the worst possible moment, completely unrelated events caused a sudden, massive increase in police presence on the streets?
The protagonists could make it work for them, perhaps even provoke the incident by sending the powers that be proof positive that, say, a terrorist cell, or mad bomber, is at work. Or they could opt for something a little more mundane, like rigging the traffic control so that it makes the streets impossible to navigate. That might make a Chase scene all that more difficult for the pursuers. Of course, it does mean you'll want to plan out your escape route in advance, but that's what Preparedness is for.
Of course, it could be something neither the protagonists nor the OPFOR anticipated: a completely random event, like a riot, gang shooting, fire, power station fire, train crash or other significant crisis. The police, emergency services, even the army could be called out. Spot checks, blockades, and other choke point hazards could end up blowing someone's Cover, and then all bets are off. This is less a chase scene moment and more a tense game of cat and mouse, as both sides try to navigate safely past the hazard towards the objective.
A third option could be to have it be something that the OPFOR provokes, possibly by accident. After all, in the Marseille example, the incident's sparked off by a handful of heavily armed dimwits, who happen to find the one thing they really shouldn't have shot at. Any other day, and it wouldn't have been a problem, or at least not as much of one.The Conspyracy has plenty of knuckleheads on its payroll; after all, someone has to do the heavy lifting. Maybe one of them got a little careless. The wrong kind of carelessness at the wrong time - say, when the protagonists are about to infiltrate an OPFOR facility - could make life difficult for everyone.
In game terms, the increase in public security caused by the Marseille Option is represented by Heat. Ordinarily the characters always have Heat 1, representing the fact that, just by existing and doing what they do, they attract some notice from the powers that be. In the event of a major special event, Heat automatically goes up by +1, so base Heat is 2. This represents the fact that the police, and possibly more than the police, are on high alert. They're not looking for the characters specifically, but anyone who looks even remotely dodgy is going to get their attention, because right now they're amped up and ready to go. The target doesn't matter so much any more, not when you're full of adrenaline and convinced you're about to get into a shooting war.
In any Chase scene where the Marseille Option is in effect, Difficulty is automatically going to increase. Again, this doesn't represent specific OPFOR action or police tactics; it just means that travel for everyone right now is a nightmare. Where Difficulty is usually 4, now it is 5, possibly more, depending on the circumstances. This applies equally for all involved in the chase.
If this is a Marseille Option that the protagonists deliberately caused, as cover for their own activity, then a Preparedness check, minimum Difficulty 4, reduces their Chase Difficulty by 2. So in those circumstances the OPFOR is at Difficulty 5 minimum, while the protagonists are Difficulty 3. The police, if they get involved, are either Difficulty 4, or 5. Difficulty 4, if the Option is something they have some control over, like a series of police blockades set up to catch a terrorist; Difficulty 5 if it's something they have no control over, like all the traffic lights in the city going wrong at the same time.