This deal was from a duplicate at Bramhall and Cheadle.
South decided that scientific investigation was not the order of the day and blasted six notrump*.
On a heart lead South won, played a club to table and took the spade finesse. With twelve tricks in the bag now declarer, tired and happy that the contract was making, just claimed. This was rather feeble, there are enough entries to cross in clubs again and take the diamond finesse. A slight improvement would be to assume that East has the spade length which is likely given West's two heart bid. So cash the second top heart and the top spades and then run all the clubs. The end position will be as below, with East to discard on the final club.
If East started with the diamond king she will be forced to bare it, a show up squeeze, if West started with the diamond king singleton then the ace will drop the king, a small extra chance.
*South could have used Roman Key Card Blackwood over three clubs to find that partner had the top honours and then bid five notrump to check for the diamond king.