The Only Making Slam

This is a deal in the last segment of the Asia Cup Trial for Open series in Hong Kong.

I sit East and reached a nice slam.

West 1 1 3 2 6 3	North 1  Pass Pass	East Dbl 4 NT 6 NT	South 2  Pass AP	Board 28 IMPs N-S Vul	Q 10 9 8 6 3 2  10 9 7 6  Q  10
				—  K Q J 4  7 6 3  K Q 9 6 5 3			A K 7  A 3 2  K J 9 8 5  A 2
1. 11-21  suit or 14-19 BAL 2. Extras 3. 1/3 Keycards, Q, with a void				6 NT East Lead:  4	J 5 4  8 5  A 10 4 2  J 8 7 4

When the 10 appears under  A, I decided to finesse South for the J to bring home my contract.

At this vulnerability, NS had a bid and raise with a total of 10 HCP.
It is likely that North was bidding with shape and he probably have 6-7 cards spade to justify the bidding.