What makes Ruthless Empire work is the intensity of Cole's obsession. He's not a hero who happens to fall in love, he's a force of nature who decides Silver is his and refuses to accept any other outcome. That level of fixation can be uncomfortable, but Rina Kent writes it with enough emotional depth that it never feels cartoonish. There's a vulnerability underneath Cole's ruthlessness, and the slow reveal of what drives him gives the story real weight. Silver, for her part, is no pushover, and watching her resist him while being inexorably drawn to him is fascinating.

The power struggle between them is a constant battle for control, and every scene crackles with tension. Cole crosses line after line, and Silver keeps pushing back, and the push and pull between them is electric. The obsession borders on dangerous, which is exactly what the book promises, but there's also a surprising amount of heart buried underneath all the darkness. Rina Kent has a gift for making morally gray characters feel genuinely compelling, and Cole and Silver are perfect examples.

The narration by Shane East and Keira Stevens is outstanding, as always. East captures Cole's predatory intensity perfectly, while Stevens brings Silver's resistance and hidden vulnerability to life. At 11 hours and 45 minutes, it's the longest book in the series, but it never feels slow, the tension sustains the whole way through. If you've read Vicious Prince, you'll enjoy seeing more of this world, and Ruthless Empire is a dark, addictive listen on its own. Rina Kent has done it again.