diverge

(of lines or paths) To run apart; to separate; to tend into different directions.

(of interests, opinions, or anything else) To become different; to run apart; to separate; to tend into different directions.

"Both stories start out the same way, but they diverge halfway through."

(of a line or path) To separate, to tend into a different direction (from another line or path).

"The sidewalk runs next to the street for a few miles, then diverges from it and turns north."