Trick 1
Declarer (Belladonna) wins the trick with the ♠K !!!   Why ?
The bidding shows West with a 6-card spades suit. East had a singleton, gone after the first trick.
But Belladonna wants Baird to believe her Partern (East) has the ♠10. This would be a vital card to set up Baird's spade suit.
This keeps West away from Declarer's weak suit ♣. The lead of the ♣K (by an experienced player) would spell defeat of the contract. (The bidding suggest East holds at least 6 clubs.)

Keep in mind that this deal is played in a teams competions. An overtrick alters little to the score (in terms of IMPs), but a Game contract defeat would be a massive result.