来龙去脉 [- lónɡ qù mài]sequence of events [actions]; cause and effect; origin and development; the ins and outs; the way(s) and wherefore(s) (of sth.); the entire process; the way it comes and the way it leaves; the whence and whither:
•¶ 这个问题的来龙去脉你清楚吗? Are you clear about the ins and outs of the problem?