Between A Rock And A Hard Place

PREMISE: The player's Adepts stumble upon a group of Supernaturals locked in a war with one another and, whether they like it or not, get caught up in the conflict. Each side demands that the players fight for them, and if the players refuse they will turn hostile and spread word among their own kind to act against the player's Adepts. This puts the players in a real bind, should they take sides, should they fight against both or neither? 
The level of danger the players will fear in this scenario depends entirely on the type of Supernaturals they are encountering. Two rival packs of feral Vampyres will inspire some anxiety, but if instead the Storyteller has the players run into a war between a powerful coven of Dark Witches and Werewolves, things might seem a bit more dangerous because these groups of Supernaturals are more established and powerful. The level of danger is equal to the power ratings of the participants in the feud. 
When the players stumble across the conflict don't give them too much time to think things through. If they stumbled across the conflict while the Supernaturals are already engaged in combat, than in real-time the player's Adepts would have only a few moments to decide. If the players opt to run away, you can either have the surviving group of Supernaturals hunt them down later or have something happen that blocks their exit from the scene.
THEME: I supposed this type of story could best be described as a "imminent threat thriller," the kind of story found in a lot of military fiction thrillers. The characters are forced into a political and military bind from which extricating themselves seems impossible without making powerful enemies. 
RESOLUTION: If you want to be a cruel Storyteller you can force your player's Adept into the war no matter what. Most Storytellers will probably let their players find a way out provided they display truly ingenious and quick-footed thinking. If the players do take up one side against the other, this will open the door for further stories down the round as the players must come to terms with the repercussions of their actions. The Supernaturals they snubbed will eventually come around looking for revenge and somehow the players are going to have to deal with them, once and for all.