Clue

My son’s girlfriend set him a surprise birthday treasure hunt through Oxford this afternoon. He didn’t know that she and I have been conspiring for a few days so when he found himself not far from our house he rang to ask whether the two of them could come round. I didn’t say his birthday meal was almost ready, and soon afterwards the penultimate clue brought him to our front door then the final one to the treasure-island cake that she had assembled in our kitchen earlier in the day. We've spent a good evening together.

These clues were on tea-dyed paper, sealed with sealing wax and tied with raffia. Not one went missing from its hiding place, though she had duplicates in case of disaster.