Possibly a fantasy roleplay involving military negotiations between two nations or a survival situation, where two enemies have to work together to survive in a hostile environment the will kill them both if they don't work together. Maybe its a breach of containment in a research lab or possibly someone of us is one of the subjects or researchers in a lab or maybe you work with people diagnosed with severe mental disorders or problems after serving in a war or being caught in a cataclysmic event. I got lots of ideas. Tell me if these suit you or if you need more.