They stepped off the train at Nollendorfplatz.  Tom read from his phone.

                  “It says to meet under the clock opposite the Metropol.  There’s the Metropol.”

                  A large auditorium-like building stood near the elevated train station.  They’d seen it several times that week as they visited various parts of the city.

                  The stairs down from the track led to a small plaza.

                  “And there’s the clock,” said Eric, who had seen it first.  He cocked his head.  “Are you hearing, something?” he asked.  “A buzzing sound?”

                  “No,” said Tom.

                  Beneath the clock were a collection of bike racks.  Another couple, a man and a woman stood there.

                  “Are you here for the tour?” Tom asked, with a smile.

                  “Yes,” they said together.

                  They introduced themselves.  Tom and Eric visiting from Los Angeles.  Janet and Marcus, from outside Berlin.  Marcus taught English literature to German college students.  Janet had come along for fun.

                  “Are you guys hearing a noise?” Eric asked.

                  “What noise?”

                  “Like a buzzing sound.  Ever since we stepped off the train.”

                  “I hear it” agreed Janet.

                  “It’s probably just the vibration of the train tracks,” said Marcus.  “We’re standing directly under them.”

                  In a few minutes they were joined by the tour guide, Brendan, a fit older man, bald, with a white beard.  He wore a white shirt and jeans.  The day was hot.  Two more arrived:  an English man and woman.  It was just after the meet-up time.  The group made small talk as they waited for two more.  A single man arrived, explaining that his friend had decided not to come.

                  So they were eight when the tour started.

                  Brendan began by telling the story of Christopher Isherwood in 1929 accepting Auden’s invitation to come to Berlin.  They were looking for a place to write but more so, the guide said frankly, “looking for boys.”

                  The group started down Maassenstrasse.  Brendan shared photographs of the neighborhood at the time.  Bombs during the war had destroyed the buildings near the tracks but away from the station there were still original buildings.  The guide had a notebook with examples of paper currency from the time.  Astronomical inflation decimated the economy:  a thousand mark note, a hundred thousand mark note, a million mark note.  He had a photo of children playing with a kite they had constructed from paper money, because it was cheaper to use the bills themselves than to use them to buy paper. 

                  “I’m sorry,” Eric interrupted.  “Are you hearing a buzzing sound?”

                  Brendan answered.  “I am.  I’m sorry.  Something to do with the electrical wires and the humidity, I believe.”

                  “It’s gotten louder since we moved away from the train tracks.”

                  “I hear it now, too,” confirmed Tom.

                  “It comes and goes,” assured Brendan.  “If it’s bearable, let’s continue.”

                  They turned down Winterfeldstrasse.  They stopped beneath a plaque affixed to the building where Isherwood had lived.

                  By 1929 the woman who owned the building had become a landlady, renting every room:  a bartender in one, two prostitutes in another.  Isherwood had the front apartment.  His friend, Jean Ross arrived later when a room opened up.  She was an English girl Isherwood had met at the clubs, the inspiration for Sally Bowles.

                  “I’m sorry.”  One of the group spoke up.  “Is it cicadas?  It’s really quite loud.  Do you have cicadas, here?”

                  Brendan looked uncomfortable.  “Let’s move further down the block and see if it’s quieter there.”

                  At the corner, they turned up Eisensacher Strasse.  If anything, the noise was louder here.  People on the street met their eyes with scowling expressions and hurried past.

                  They turned left at Motzstrasse.  At the corner of Kalckreuthstrasse the guide stopped them again and attempted to explain how this building, now a grocery store, had been the site of the largest cabaret in Berlin:  the El Dorado.  He had a photo of the interior with prostitutes drinking at the bar and people of indeterminate gender dancing together on the floor beyond.  He had a second photo of the building after the conservative Catholic political party had joined with the Nazis and closed the bars.  The building had become a field office for the Nazi party.

                  “What is that sound?” the English woman complained.  “I can barely hear you.” Her husband excused them. “I’m sorry,” he said.  “It’s all very interesting, but this is intolerable.  We have to go.”  They left the group.

                  The rest huddled closer.

                  “Is it everywhere?  Is it the whole city?” Janet asked.

                  The noise had become pervasive.  A piercing, buzzing, shocking intensity, seeming to come from all directions, even above from the clear sky.  Not a pitch, but a white noise cluster assaulting the air. On the verge of painful, and growing more pointed, impossible to ignore.

                  The tour guide tried to keep order.  “We’ll walk back to the station.  Maybe we’ll find someone who can explain.  I’m sure it will be over soon.”

                  They walked up Kalckreuthstrasse to Kleiststrasse and turned back toward the train station.  An emergency vehicle screamed past, its siren rising only slightly above the background roar.  Brendan shouted, loudly above the din, the story of Isherwood in 1933 finally leaving Berlin after witnessing a massive book burning.  Tom, Marcus, and Janet, leaned close to Brendan, straining to hear.  Eric gave up, walked ahead, holding his ears closed.  The single man had disappeared. No one had noticed him leave.

                  Now the cafes were empty.  Gallery owners and shopkeepers shut their doors.  The few people still on the sidewalks ran quickly to wherever they thought they had to go, holding hats or newspapers tightly against their ears.

                  “My God,” groaned Janet.  “What is going on?!”

                  In sight of the train station now, she and Marcus turned and half-bowed to Brendan, and then, speech being no longer possible, broke away without a further word and sprinted toward the train station.

                  Brendan usually ended the tour by showing a bronze tile embedded in the sidewalk in front of an apartment building inscribed with the name of one of the thousands of former residents who had been transported east and murdered.  He pointed toward it, desperately.

                  The terrible noise obscured all other senses.  Tom pressed his fingers into his ears.  He squeezed his eyes shut until they watered.  It felt as though a cold knife was entering his chest.  

                  Brendan fell to the ground.

                  Eric reached for him but the pain forced him to return his hands to his ears.  He and Tom took several steps back, hoping they could still get away.  But by then it was too late.