After 10 years of travelling abroad, Alex Karanicholas returns to Melbourne unannounced. He goes back to a big old house with a tower, divided into apartments, looking over a creek in the inner north. His widowed mother, Aspacia, has been waiting for him.

Alex's cousin Mick also lives in the house. During Alex's long absence, Mick has helped Aspacia care for the property, rejuvenating the vegetable garden and cleaning the neglected creek. Alex discovers that his cousin and his mother share a secret. Both had known the hidden occupant of a corrugated iron shack shrouded in blackberries and bushland on the opposite side of the creek. Alex's father had forbidden Alex and Mick from crossing the water and visiting the bush block. But when Alex was still at school he tried to discover who lived in the hut. His excursions to the bushland over the creek had been the great solitary adventure of his childhood. The secret man had not been seen for many years; Mick tells Alex he never knew his full name or where he came from.

Alex revisits the hut, drawn by the childhood mystery. He unearths a lost cache of paintings and photographs and revisits his family's dark history, encompassing the German occupation of Crete, the Greek resistance, the death of Mick's parents and an orange farm in Mildura.

In the meantime, Alex's reappearance in the house triggers a wave of reaction among the other occupants. Maggie O'Malley and her son Josh leave for her brother Tom's farm before Alex has a chance to meet them. Natalie Harper hopes Alex will intervene to save her and her husband Greg from eviction, and Maggie's lover Darce starts drinking again.

When a flood bursts the banks of the creek and topples the hut, all the occupants of the big house are forced to find a new place in an altered landscape.