When a combatant prepares to “cross over,” wish him well. It means he’s leaving to work deep undercover in a hostile country. It’s a simple term, but it signifies great courage and danger. In the dangerous game of espionage, being a combatant is the most dangerous work of all. He will be exposed to danger every single moment he is gone. Crossing Over has other meanings as well, including a change of allegiance by an intelligence officer. The happiest meaning of the phrase is the one we see here—people crossing a wooden foot bridge in London’s Hyde Park.