Icy city spies will infiltrate close to Poyang Lake (7)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

( LA [Los Angeles; American city] + CIA [Central Intelligence Agency; spies]) contained in (will infiltrate) G ( final letter of [close to] POYAN G) + L (LAKE). Poyang Lake is the largest freshwater lake in China)