when the dead come home (on Halloween)

Halloween is All Hallows' Eve, the vigil of All Saints on 1 November, with All Souls following on the 2nd. Its older layer is traced to Samhain, the Gaelic feast closing the harvest, when the line between the living and the dead was thought to thin. In the ninth century the Church fixed All Saints on 1 November; All Souls followed on the 2nd around the turn of the millennium. Medieval Britain and Ireland filled the gap with "souling", the poor going door to door offering prayers for the dead in return for soul cakes, and with "guising", disguised visits that Irish and Scottish emigrants carried to North America, where they became trick-or-treating.

Beneath the Christian calendar lies something older than private grief: a yearly pact between a society and its dead, who were invited in, fed and sent away again. On the last day of the Anthesteria, the spring wine festival, Athenians believed the spirits roamed the city. Households chewed hawthorn and daubed their doors with pitch, cooked a pot of mixed grains for Hermes of the underworld, and at dusk dismissed the visitors with a formula: out, spirits, the festival is over. Boiled grain for the dead survives in the Orthodox kollyva and in southern Italy's "wheat of the dead".daubed their doors with pitch, cooked grain for the underworld and dismissed the roaming spirits at dusk. Rome split the dead in two: ancestors honoured with tomb meals at the Parentalia, restless ghosts bought off with black beans thrown at midnight during the Lemuria. Sicily is Persephone's island, the girl carried below the earth near Enna. Her husband Hades was also Plouton, "the rich one", because grain and wealth rise from beneath the ground. In that light the dead are the givers of abundance, and it makes sense that they bring the presents. 

Spain keeps Todos los Santos with cemetery visits, marzipan huesos de santo and stagings of Don Juan Tenorio. Beneath it runs an older country. In Celtic Galicia, 31 October is still Samaín, once marked by turnip skulls lit from inside, and the Santa Compaña, a candlelit procession of hooded souls, walks the lanes at midnight: meet it and you die within the year. Each chestnut eaten at the autumn magosto was said to free a soul from purgatory.

Spain carried the feast across its empire. Across the Atlantic, the Aztecs held their own feasts for dead children and adults. Mexico's Día de Muertos joined it to Mesoamerican rites: altars with photographs, marigolds, the favourite dishes of the dead, pan de muerto and sugar skulls. 

Sicily, under Aragonese and Spanish rule for more than four centuries, keeps a close twin in the Festa dei Morti on 2 November, when the dead return in the night with presents hidden for the children to find. Its marzipan fruit, sugar figures (pupi di zucchero) and bone biscuits are cousins of the Mexican calaveras. The sugar craft behind both came with the Arabs, and Mexico still calls it alfeñique, from the Arabic al-fanid. In both places the dead are family, not monsters; they visit rather than haunt.

Sicilian children never had to beg from strangers, because their grandparents brought the presents. The dead were said to shop at Palermo's fiera dei morti, and children prayed to the "almi santi" for generosity, warned that if they misbehaved the dead would scratch their feet instead. In the 1970s the dead favoured guns: cap pistols and pellet-firing replicas such as the Interpol, which turned the morning treasure hunt into a shoot-out and filled casualty with injured eyes. Some of Palermo's dead never left at all: 8,000 mummies still line the Capuchin catacombs in their Sunday best. Now pumpkins have reached Sicily, and the dead who once brought the gifts compete with a feast where the children do the begging.