Tears ran down Eberhard's cheeks. His face was red and sweaty. Interrupted by heavy breathing, he screamed out fragments of sentences, "all this beauty," "we would have all come back," "we should have done like the Romanians did" and, later, "we should have killed them all."
Eberhard was standing on a view point above the wide empty plain of the volcanic crater in La Réunion, an island in the Western Indian Ocean. The other tourists, initially unaware of his state, taking photos and exchanging smiles and kisses, became silent. They looked away. Eberhard shook his head. "How is it possible that someone had the right to prohibit someone else to see all this beauty?" he asked.
I met Eberhard in 1998, on his first trip to what he described as an 'exotic island destination'. I was studying social transformations in La Réunion brought about by the development of European mass tourism. To be able to talk with tourists, I worked for two years as a tour guide and driver for a local tour agency.
The aesthetic emotion induced by the sight of the volcano generated a deep anger.
It was not uncommon that the tourists I guided spontaneously started to cry, laugh, smile or felt faint when surrounded by something they found beautiful or captivating, or deceiving. Certain spaces, such as the volcano, usually left them speechless.
Seemingly unable to find words for what happened in their mind, many were left with their eyes and mouth wide open, inhaling air, shaking their heads. Some were so overwhelmed by what they saw that they felt they needed to sit down 'to keep their balance' or shake their heads to 'come back to reality'.
Why such strong responses to what seem anodyne, mass-produced and mass-consumed tourist attractions? I realised that tourist sites were in most cases merely triggers for people to engage in inner dialogues and existential journeys that were unrelated to the actual encounter.
In the evening after his breakdown, having a beer before dinner, Eberhard started to talk about his emotions at the volcano. He told me that he was from East Germany and while under the ruling Socialist regime, travel outside the (former) German Democratic Republic (GDR) had been strictly regulated. 'Let us out!' was one of the refrains shouted during the Monday demonstrations in East Germany that preceded the eventual fall of the Berlin Wall in November 1989.
The promise of travel to places beyond the Iron Curtain was a bribe used to gratify citizens for their work and submission to the political rule of the Socialist party. Refusing to grant travel permission was a way to punish those with whom the regime felt uncomfortable. Following the opening of the borders, Eberhard, along with millions of other East-Germans, travelled for the first time to countries in Western Europe, the Caribbean and the USA.
For Eberhard, then, the aesthetic emotion induced by the sight of the volcano generated a deep anger. For him, the denial of the right to travel seemed not just a matter of a regime inhibiting luxury activities, but a denial of freedom of the most inhuman kind. Referring to the strict travel regulations under Socialist rule, he questioned how "some people could prohibit others to see such beauty." "We would have all come back" , he affirmed.
During the 1989 revolution in Romania, following a brief military court trial, the long-standing leader of the country's communist party, Nicolae Ceauşescu, and his wife Elena were executed. Images of their dead bodies were circulated in the media around the world. Picking up on the way in which the Romanian revolution had thus been concluded, Eberhard exclaimed that "we should have killed them all" — referring to the leaders of the former GDR (who were not executed; only few went to prison).
Extreme emotional responses by ordinary mass tourists, such as Eberhard's, are neither unique nor particularly astonishing. Experiences of extreme awe in particular sites have been observed for hundreds of years. One occurrence is related by Berta Spafford-Vester, a late 19th century American emigrant to Israel. In her memories, she describes various characters encountered in Jerusalem who, overwhelmed by spirituality, temporarily lost their references and identity thinking they were saints on a holy mission. 
In a more contemporary context, various authors relate cases of Japanese tourists who suffer from what is now called the 'Paris syndrome'.  Similar forms of 'travel syndrome' were observed in Florence and Jerusalem, generally characterized by psychiatric symptoms such as acute delusional states, hallucinations, feelings of persecution, depersonalization, and anxiety, and also by psychosomatic manifestations such as dizziness, tachycardia and sweating.
According to Magherini a psychiatrist treating tourists affected by travel syndromes in Florence, the combination of anticipation, stress, culture shock and the deep veneration of artworks is able to pull pre-existing trauma to the surface. Similarly, most if not all patients affected by the Jerusalem syndrome seemed to have had previous mental conditions which the journey managed to bring to the surface.
These extreme cases indicate what happens in a more subtle way in most forms of ordinary mass tourism. Taking people out of their everyday context has a way of disturbing and destabilizing their normal perceptions of their lives. Travel challenges them to reflect about their desires and forms of belonging, about their fears of loneliness, time, mortality and the (hopefully not too) soon-to-come event of death. The emotional journey of ordinary mass tourists, then, goes far beyond the idyllic yet sanitised visions promoted on tourism posters in railway stations and airports around the world.
Regardless of what kind of travel one does — island resort, cruise ship, backpacking — tourism opens the possibility for emotionally challenging experiences. How we respond depends upon our personal experiences, our histories, and our culture. Not everyone's reactions will be as strong as Eberhard's.
Yet in a sense we all risk ending up trying to kill someone on the edge of a volcanic crater when we step outside of our ordinary lives and dare to become tourists.
This article is adapted from the introduction to the book Emotion in Motion: Tourism, Affect and Transformation, edited by David Picard and Mike Robinson (Ashgate 2012).