What is the solution to book Who Killed Jock Ewing?

The answer to the question "Who Killed Jock Ewing?" is a bit complicated. It's a major plot point in the television show Dallas, not a book.

Here's the breakdown:

* The initial suspect: The show heavily implied that J.R. Ewing was the one who killed Jock. The final scene of the season had J.R. aiming a gun at Jock.

* The truth revealed: The next season revealed that J.R. didn't pull the trigger. Instead, Jock was accidentally killed by a falling piece of wood while attempting to mend a fence.

* The twist: J.R. was the one who hid the truth to protect his family and avoid scandal. He manipulated the evidence to make it appear as though he was the killer.

So, J.R. Ewing didn't kill Jock, but he lied about it and ultimately benefited from Jock's death.

Note: If you're interested in exploring the world of "Dallas" beyond the television show, there are several novels and tie-in books based on the series.