The execution of Sir Nicholas Carew is actually the opening scene of The Path to Somerset: it was the perfect backdrop to set the tone for how much Henry changed since Jane’s death.
Sir Nicholas Carew was a boyhood friend of Henry’s; he was also instrumental in helping Jane supplant Anne Boleyn. He was executed for his part in the Exeter Conspiracy, which was intended to replace Henry with a Catholic alternative, though the conspiracy was somewhat half-baked and Carew’s participation was somewhat questionable. Many people believed that Cromwell had trumped up the charges to remove adversaries to his reforms…as I say in the scene (or, rather, Edward says in the scene), it would not have been the first time.
If you squint a little, you can see that this is the pattern by which pretty much everyone around Henry lost their lives: they would do something small that seemed to prioritize their own interests, then their enemies would pounce. In Carew’s case, he insulted the King after a game of bowls and also refused to trade lands with him, acts of disloyalty which left the King receptive to the allegations of treason. In Cromwell’s case, he saddled the King with an unacceptable bride to further his own religious leanings, so of course he was guilty….As I said, this was a dangerous time in Henry’s court.
(PS this opening scene also set me up beautifully for the END of the book: less than two months before Henry’s death, Stephen Gardiner was banished from the King’s presence and crossed off the list of the planned Regency Council. Why? Because he refused to trade lands with the King! You know what they say: those who cannot remember the past are condemned to repeat it!)