Booby trap is very hard to see
Erik Weihenmayer, the only blind person to reach the summit of Mount Everest, said, “People get trapped into thinking about just one way of doing things.”
This deal contains a nasty trap that would catch almost everyone. You have the benefit of seeing all 52 cards. How can South make four spades after West leads the club ace?
North’s three-club rebid was a double negative, indicating some 0-4 points. South’s three hearts was forcing, but North’s three spades was not.
At the table, we would ruff the club ace and cash the spade ace, then recoil in horror at the 4-0 split. We would no doubt continue with the heart ace, heart king and heart four. Here, though, West would ruff with the spade nine and shift to the diamond two. East would win with his king and give partner a second heart ruff. Then the diamond queen or a diamond to the ace would set the contract.
If South anticipates the bad breaks, he will discard a diamond at trick one; and if West leads another club, declarer should ditch his second diamond. Then, when West ruffs the third heart, which costs his natural trump trick, he cannot reach his partner for the second ruff.
Perhaps you noticed that ruffing at trick one was not fatal. After cashing the majorsuit aces, South must exit with a diamond to start cutting the defenders’ communication. East can win and play a heart, but South will win and lead another diamond. East takes that trick and gives West a heart ruff, but, again, that costs his trump trick.