A supposedly true book about a Soviet submarine that attempted to fire a nuclear missile at Pearl Harbor in 1968 and blame it on the Chinese. There's a lot of conjecture, but a lot of circumstantial evidence to support his claims.... and the author connects a lot of dots. If even half of what he argues is true, then there's still a shitload of support for his theory.
In summary, it looks like the US was 3 seconds from getting nuked during the Cold War. The KGB agents that took over the sub didn't know about the final missile fail-safe that prevents unauthorized launch. The fail-safe itself was a naval secret, and the KGB and Soviet navy were always at odds with each other. Apparently.