Do themes come in twos or threes?

It is an old wive's tale that unusual things happen in threes. So, I am expecting to see today's play theme again soon. It was in the book I reviewed yesterday, Last Call in the Menagerie. And here it is in The Canterbury Bridge Tales by David Silver and Tim Bourke (Master Point Press).

This book is a collection of nine stories by Silver, each containing one or two deals from Bourke. Most of these are slams requiring some type of squeeze. This is the easiest in the book. How should South play in six spades after West leads the heart jack?

East made a modern weak jump overcall - when nonvulnerable, pre-empt with a poor hand, even if the suit's quality is wanting. South's four clubs was a control-bid expressing slam interest. North, although he had a minimum opening, did hold two aces, so he control-bid four hearts. Then Blackwood led to the slam.