The bidding: South, with 13 HCP’s, no five-card major and longer Clubs than Diamonds, opens One Club. West passes with his poor 11-count. North bids his four-card major, and South cannot rebid One No Trump with a singleton in partner’s suit.
The responder may have a singleton or void when he either has to bid a new suit at the two-level with less than 10 points, which is wrong, or bid One No Trump. However, the opener may not.
South, therefore, rebids his five-card minor.
This is the first case of two cases when one rebids a minor with five cards. Normally rebidding a minor shows six cards.
The Play: West does not have a good opening lead. A lead from Qxxx in trump is okay unlike from Qxx, but the Heart Ten is probably the least objectionable.
A small Spade would turn out to be interesting but risky. Underleading an Ace is rare, but is done when dummy likely has the King and partner, the Queen.
West’s four Clubs may suggest declarer has only five Clubs, then he has Spade shortness, and the Spade lead is too risky.
Declarer wins the Heart Queen and draws two rounds of trump. He then plays a Spade to the King and West rises with the Ace. A Diamond will go on the Spade King.
Note: Had the Spade Ace been offside, the way to play the diamonds is to play small to J10xx and then run the J through East. Hopefully West pops up with an honour then West can be finessed.