The PPP is a secret oganization tasked with keeping Equestria safe. No pony knows who they are; their agents blend into the background just like any other pony. With their expertise, keeping the unicorn Twilight Sparkle safe should be no problem.
The PPP has a long history of keeping Equestria safe. A long and often untold history. When a sect attempts to resurrect an ancient spirit, old, harsh truths come to light and threaten the foundation of this secret agency.
Will Lyra and Bon-Bon's secret relationship stay such after Pinkie Pie hears that it's their anniversary and decides to throw a "Best Friends Anniversary" Party?