six
o'clock
Then , what a glorious afternoon they had on the smooth beach , hunting for shells and digging in the sand . How Andrea laughed when his father took him away out and let the breakers roll over him . Then Maria , holding tight to her brother 's hand , who still seemed much bigger and stronger , even if this was her birthday , ventured far into the waves . Much too quickly the happy hours sped , and before they knew it it was six o'clock . All the way home on the steamer Andrea held tightly to the dried starfish he had found on the sand , while Maria was the happiest child in Venice , with a brooch made from the pearl shell of the Lido , which Luisa called `` fior di mare , '' or flower of the sea . As they stumbled sleepily across the Square in the darkening twilight , holding fast to the hands of their mother and father , their ears failed to catch the faint cheep of a baby bird in distress , and they reached home entirely unaware of the tragedy that had happened in pigeon-land . When Paolo called for the children Monday morning , there was an air of mystery about him that was distinctly puzzling .