Monique discovered that the original manuscript of Schnabel’s book was stored at the German Literature Archive Marbach near Stuttgart, Germany. When she contacted the archive, she was told that part of Schnabel’s personal notes and some of Otto Frank’s letters were available as well. Schnabel had not made recordings of his interviews, and some critics argued that he’d been imprecise in his notes. Regardless, it could be valuable to examine the notes personally. Maybe she’d find corroborating evidence to support Kugler’s assertion that Silberbauer had demanded, “Where are the Jews?,” clearly indicating that he’d been tipped off about their presence in advance.
Monique set out for Germany with the researcher Christine Hoste. After an eight-hour drive in wind, rain, and light December snow, they arrived at a deserted hotel near the archive. There were no other guests, which enhanced the feeling of diving into unknown territory. Given the strict German bureaucracy, it had not been easy to get permission to look at the notes in the archive, but when they arrived the next morning, after some misunderstanding, the papers were more or less ready for their perusal. The two women were escorted to a small room with a glass wall （so the librarian could keep an eye on them）， a Formica-topped table, and retro lamps.
Schnabel’s notes were in German in old-fashioned cursive writing. Some were not difficult to read; others felt like a puzzle with words scribbled in corners. At the time of writing, either paper was still scarce or Schnabel had retained the wartime habit of not squandering it.
Monique and her colleague worked feverishly. Monique said it was strange to feel so close to Otto, knowing that he’d held some of the papers and letters in his own hands. This was no longer just history. Reading the notes felt personal.
Suddenly Monique said to Christine, “Here’s the evidence!” She’d found two instances in Schnabel’s notes from different interviews in which he’d copied the sentence “Wo sind die Juden?” （Where are the Jews?）。 To judge from the notes, the helpers apparently agreed with Kugler’s first memory—that the raiders specifically demanded to know where the Jews were hiding. That was exciting. It meant that Silberbauer and the Dutch detectives were not looking for food coupons or weapons; they did not happen on the hiders by chance.
There was another mysterious scrap of paper among Schnabel’s notes. It was simply the end of a sentence: “。 . . and she knew the betrayer.” There was nothing more. The “she” would likely have been Miep, certainly not Bep. Otto did not confide in Bep, and Miep was the only one who had ever claimed to know the name of the betrayer. Had Miep told Schnabel what she knew? Schnabel had died in Berlin in 1986. If he had known the name of the betrayer, he had never disclosed it.
There was still another piece of the puzzle to investigate, however. If there was a betrayer, as the Cold Case Team was now convinced there was, did the tip actually come, as had always been assumed, through a phone call? How prevalent were phones in homes during the war? Were there public phones on the streets that could easily be used by a potential informer? To find out, Vince and Brendan turned to Jan Rijnders, a historian and expert on Netherlands telecommunications during World War II, who provided the team with a report on the public phone system （PTT） during the war.
Four days after the Dutch surrendered on May 15, 1940, the German authorities appointed Dr. Werner Linnemeyer director of the municipal telephone services. Huge amounts of cables and equipment were stolen for the German military, but, according to Rijnders, that only meant that the high quality of the Dutch network dropped to a lower level. By 1944, only a few private homes still had a telephone, since a permit was needed to own a phone. Though public phone booths on the streets had been dismantled, most functioning businesses still had a phone. The cold case researchers tracked down a telephone directory for 1943. There was no edition for 1944, but that is not proof that there were no more phones; it’s just as likely that there was no paper on which to print a phone book.
After September 1944, the Germans were aware that calls could be set up by the resistance to the liberated southern part of the country. They therefore switched off all long-distance exchanges, but generally local calls still functioned, in part because the Germans wanted to continue to wiretap local businesses as well as their own personnel.7
Anything the Cold Case Team knew about a phone call initiating the Annex raid came from Silberbauer. In his testimony to Austrian authorities, he stated that at 10:00 a.m. on the fourth, a call was received by SS Lieutenant Julius Dettmann of Referat IV B4, who then ordered Silberbauer to carry out the raid along with a number of detectives chosen by Sergeant Kaper.