At first Greta was skeptical about the plan. “But, sweetheart, even if we succeed, what’s to stop the Germans just rerouting calls around the network?”
“Volume of traffic. The system is overloaded. The army command center called ‘Zeppelin’ outside Berlin handles one hundred twenty thousand long-distance calls and twenty thousand telex messages a day. There will be more when we invade France. But much of the French system still consists of manual exchanges. Now imagine that the main automatic exchange is out of service and all those calls have to be made the old-fashioned way, by hello girls, taking ten times as long. Ninety percent of them will never get through.”
“The military could prohibit civilian calls.”
“That won’t make much difference. Civilian traffic is only a tiny fraction anyway.”
“All right.” Greta was thoughtful. “Well, we could destroy the common equipment racks.”
“What do they do?”
“Provide the tones and ringing voltages and so on for automatic calls. And the register translators, they transform the dialed area code into a routing instruction.”
“Would that make the whole exchange unworkable?”
“No. And the damage could be repaired. You need to knock out the manual exchange, the automatic exchange, the long-distance amplifiers, the telex exchange, and the telex amplifiers-which are probably all in different rooms.”
“Remember, we can’t carry a great quantity of explosives with us-only what six women could hide in their everyday bags.”
“That’s a problem.”
Michel had been through all this with Arnaud, a member of the Bollinger circuit who worked for the French PTF-Postes, Telegraphes, T‚l‚phones-but Flick had not queried the details, and Arnaud was dead, killed in the raid. “There must be some equipment common to all the systems.”
“Yes, there is-the MDF.”
“What’s that?”
“The Main Distribution Frame. Two sets of terminals on large racks. All the cables from outside come to one side of the frame; all the cables from the exchange come to the other; and they’re connected by jumper links.”
“Where would that be?”
“In a room next to the cable chamber. Ideally, you’d want a fire hot enough to melt the copper in the cables.”
“How long would it take to reconnect the cables?”
“A couple of days.”
“Are you sure? When the cables in my street were severed by a bomb, one old Post Office engineer had us reconnected in a few hours.”
“Street repairs are simple, just a matter of connecting broken ends together, red to red and blue to blue. But an MDF has hundreds of cross-connections. Two days is conservative, and that assumes the repairmen have the record cards.”
“Record cards?”
“They show how the cables are connected. They’re normally kept in a cabinet in the MDF room. If we burn them, too, it will take weeks of trial and error to figure out the connections.”
Flick now recalled Michel saying the Resistance had someone in the PT!’ who was ready to destroy the duplicate records kept at headquarters. “This is sounding good. Now, listen. In the morning, when I explain our mission to the others, I’m going to tell them something completely different, a cover story.”
“Why?”
“So that our mission won’t be jeopardized if one of us is captured and interrogated.”
“Oh.” Greta found this a sobering thought. “How dreadful.”
“You’re the only one who knows the true story, so keep it to yourself for now.”
“Don’t worry. Us queers are used to keeping secrets.” Flick was startled by her choice of words, but made no comment.
The Finishing School was located on the grounds of one of England’s grandest stately homes. Beaulieu, pronounced Bewly, was a sprawling estate in the New Forest near the south coast. The main residence, Palace House, was the home of Lord Montagu. Hidden away in the surrounding woods were numerous large country houses in extensive grounds of their own. Most of these had been vacated early in the war: younger owners had gone on active service, and older ones generally had the means to flee to safer locations. Twelve of the houses had been requisitioned by SOE and were used for training agents in security, wireless operation, map reading, and dirtier skills such as burglary, sabotage, forgery, and silent killing.