The eighth and final book in the “Coptic Cross” series. It brings to an end the storylines begun in the previous books. Agents of the Department of Special Projects scour Europe in search of hidden secrets. Russian military airships are sailing in the skies of the Baltic, the Spithead roadstead, the main anchorage of the Royal Navy are marked by foamy torpedo tracks, the British battleships of Admiral Hornby's squadron are dying ingloriously on minefields laid by the ships of the "special mine division". Meanwhile, in the underground casemates of the Shlisselburg fortress, scientists, with the help of a still little-known American, are preparing a daring experiment - a breakthrough through wormholes into the world of the mysterious “four-fingered creatures.” And when they succeed, the familiar world with its cozy European world order will never be the same again. And all this will involve heroes with whom readers have already become intimately acquainted...