Other forms: nodi
A nodus is a knotty problem or a difficult situation to resolve. The nodus of something is where different things or aspects intersect, making things complicated.
In drama, the nodus is the point in a plot where the various threads of a story become entangled, leading up to the climax, after which the denouement, or "untying" of the entanglement, occurs. The famous Latin phrase dignus vindice nodus means "a knot worthy of a deliverer" — meaning a plot complication so difficult and complex that only a "god from the machine" (deus ex machina) could solve it. Historically, the word nodus has been used in fields including botany, medicine, and astronomy, to describe points where different things converge.