deus ex machina

(ĕks mäˈkə-nə, -näˌ, măkˈə-nə)

1. In Greek and Roman drama, a god lowered by stage machinery to resolve a plot or extricate the protagonist from a difficult situation.
2. An unexpected, artificial, or improbable character, device, or event introduced suddenly in a work of fiction or drama to resolve a situation or untangle a plot.
3. A person or event that provides a sudden and unexpected solution to a difficulty.