The message was urgent: "There are blackies living in cardboard boxes in fields along the golden mile of five-star hotels in St Julian's. Have we become like the favellas (slums) in Brazil?"
The woman who called jogs along this stretch everyday at 7.30 a.m. and she felt threatened after thinking that she twice saw immigrants emerging from these boxes.
She feared for her safety and jewellery, but since they went about their business she did not feel the need to cut short her exercise routine.
With a photographer in tow, The Sunday Times set out early to establish whether African immigrants were really living in primitive conditions. The phone call had all the ingredients of a recent BBC feature on a cardboard box village of immigrants in Italy.
Climbing down walls and manoeuvring through shrubs, we came across a small, haphazardly-built stone lodge covered with white jute bags and finished off with a massive plastic sheet to keep away the rain - it was so inventive it probably beats waterproofing in most homes.
Branches were scattered over the plastic sheet to camouflage the den. A thick wooden board doubled as a secure door that is padlocked when its owners are out. A small, worn mat lay at the entrance; a warm touch of home.
A makeshift porch had been created with a stone bench, sheltered by bamboo fencing. A pizza box and a plastic bottle littered the area, but there was no sign of life.
Undeterred, we returned to the site around 7 p.m. Slithering down the wet grass slope, battling the rain and gale force winds was harder this time, but we sensed some movement and saw a white light flashing in the bushes.
When we reached the edge of the wall and were about to descend the wobbly stone steps, we got an unexpected surprise: peering up at us with a quizzical expression were four Maltese teenagers.
Flashing a battery-operated neon tube that cast shadows over their faces, they burst into cheery laughter when we asked if there were any immigrants in the area.
After a humorous exchange, we established that this was no cardboard home of an immigrant, but a teenage hideout; a place where they escaped to whenever they had any free time to play or hang out.
Is the prevalent concern over the sudden wave of illegal immigrants leading to mass hysteria? Anthropologist Mark Anthony Falzon said: "Whether or not we have reached a state of 'mass hysteria', I have absolutely no doubt that the right ingredients are lined up."
The first ingredient was the spectacle of immigration. African immigrants arriving on overloaded rickety boats and appearing out of nowhere at random places along the coast, made for a heightened sense of drama.
In a small island surrounded by an empty horizon, this type of arrival lent itself to metaphors of 'invasion'.
Dr Falzon said skin colour also led to inescapable "racism", an "unfortunate corollary" of so many migrant experiences worldwide.
Perhaps more importantly, particular phenotypes were invariably linked to historical-cultural legacies, Dr Falzon said, pointing out that black people had for decades figured in the public imagination as paragons of disease and destitution.
"This is in part due to constructions of the needy native by (well-meaning) Maltese missionaries, and also to a selective coverage in the world media of what Africa is all about - wild animals or human disasters. This factor probably explains this incident of the 'Pembroke tribe': if there are people living in boxes in a field, they must be blacks, and therefore immigrants."
Another element was the spatial segregation of African immigrants. In the physical sense, immigrants in Malta were placed in overcrowded camps hedged behind fences and barbed wire.
"This spatial dynamic makes for an increased sense of crowdedness ('we are full up') and also of threat ('only those thought to be dangerous are put behind barbed wire')," he pointed out.
"Socially, black immigrants are almost completely ostracised from public discourse, which means we are failing to engage with them as rational actors in their own right," he said, adding that the two exceptions were interviews and features intended to evoke pity, and news of violence in the detention centres.
Dr Falzon said mainstream politics had abdicated from seriously discussing the issue, creating a vacuum in the public sphere, though not, crucially, in the popular one - which was where hysteria was being manufactured.