Okay.
So an accident at a secret lab in the sub-basement of [corporation] has released some kind of magically-active pollutant goo into this area of the sewers. No one really noticed at first until a maintenance worker or two wound up dead. Some drones were sent in, and got footage of a bunch of weird critters down there. Obviously the magically active critters were drawn to the localized spike in mana.
When the presence of the animals got publicized, a bunch of young Eco-activists led by "Cody" the shaman holed up in the sewers to protect them.
Because Knight Errant can't just go in and mow down a bunch of activist kids, on account of P.R., a cop has called in a favor from the team's fixer. Now they are being hired to go in, clear out the critters and get the punks out, (hopefully) with as little violence as possible, but as long as it doesn't come back to K.E. it isn't a big deal if it gets a little messy.
Of course, as the situation has escalated, [corporation] has deployed a strike team, entering at a different angle, to wipe out any witnesses, and set off an explosion, making it look like the eco-activists detonated a bomb, and covering up evidence of the seriously dangerous/creepy experiments that they were conducting in a highly populated area.
Fun!
For a moment I thought this might be too far-fetched, but then I remembered it's Shadowrun.