After traveling to an international congress in Malta, cardiothoracic surgeon Ulyana Loginova didn’t even suspect what adventures awaited her. At the hotel where she was staying, strange and mysterious people gathered—nothing to do with medicine. Each of them, as it later turned out, pursued their own goals, not always legal. On the second day on the sunny island, Ulya and her friend Dasha discover the body of their new acquaintance, a cardiologist from England named John Riddle. The doctor was strangled, and his entire room had been turned upside down—someone was clearly looking for something, but they didn’t find it. And only “lucky” Dasha noticed, next to John’s body, an old medieval ring with a Latin inscription: “By fire and sword”…