Instruct: Classify the given review into positive or negative sentiment.
Query: no happy endings here

This series is perhaps one of the darkest young adult sci-fi stories available. That is probably why it stands out so vividly in my memories from adolescence. At last having achieved Winchester's throne, Luke proceeds to unravel everything he has gained with his frustrating single-mindedness and stubborn pride. The ending so shocked me in its sadness and resignation that I can clearly recall rereading the final chapter over and over. This series, along with certain Robert Cormier novels, taught me that all stories do not end well, and in fact might be more resonant and thought-provoking if they don't. This one stays with you for quite a while.