‘He’s probably cheesed off at Luke,’ Tilly lied. ‘He’ll have to do his chores till he gets back.’

‘Ah, I did wonder if it was me.’

‘Don’t be silly,’ Tilly said hastily, ‘Why would it be? Anyway, thanks for humouring me today. At least the matter’s settled. It never would have arisen in the first place if it hadn’t been for that sergeant insinuating . . .’ She left the sentence unfinished. They rode back in silence to the homestead where she took a quick glance at the sun and said brightly, ‘You’ve still got time to take the boat out.’

‘There’s no hurry,’ he reiterated comfortably. ‘I’ll do it tomorrow.’

Home again, Tilly assauged her vague feelings of embarrassment with work. She tidied the games cupboard, a task long put off, and mopped and dusted the lounge. The mailbag caught her eye and, having hung the mop to dry on the clothesline out back, she sorted the mail, stacking the business letters on Sophie’s desk and carrying the newspapers through to the kitchen. There was a birding magazine for Luke, several circulars and the usual handful of advertising handouts from Darwin’s shops and supermarkets. Why the post office kept including them, she could never work out. Last of all was a grubby-looking letter addressed to herself.

Deeply surprised, for she received little mail beyond official notifications and the occasional note from her mother, Tilly turned it over but found no return address. The postmark was smeared, the address written in block capitals. Intrigued, she used Sophie’s paperknife to slit the envelope and slid out a single sheet of cheap, lined paper only to find that it was completely blank. Tilly stared at it, puzzled, then peered into the empty envelope and studied the stamp, trying to make out a name. Only the initial letter of K was legible – for Katherine or Karumba, or Kathmandu? Not the latter, the stamp was Australian. So who . . .? God, her life was being taken over by mysteries.

Thoroughly irritated, Tilly snatched up the junk mail, added the letter and the detritus from the games cupboard (old scoring sheets, a broken box that had once held mahjong tiles, and empty photo folders) and marched out to the incinerator. Whoever was being funny at her expense would discover that she wasn’t about to play. As far as she was concerned, anonymous communications could remain just that. She piled the papers onto the steel mesh in the blackened half-drum where the rangers burnt their rubbish, and lit the empty carton. The flames caught at once and she stood there, watching the pieces burst into flame, the junk mail and yellowed paper burning first. The blank sheet of the letter lay on the top above the envelope, whose corners now began to crisp. The draft of heat as it burnt lifted the sheet of cheap paper, and as it did so, writing appeared on its surface.