Catch partners in North America gatecrashing earlier (7)

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

A double envelope (‘in’ and ”gatecrashing’) of SN (‘parners’ – in bridge, for example) in NA (‘North America’) in ERE (‘earlier’). At a guess, some may treat this as a single envelope with contents NS NA, with ‘in’ doing nothing in particular.