My son read it out loud in instalments and, I confess to you but have not to him, that on the first night, when he’d stopped for bed a few chapters in, I continued to the end without him, so keen was I to discover the denouement. It was worth it — and just as good the next night, read again together. Lewis’s message — who’s to say your imagination isn’t also your reality? — feels particularly pertinent at the moment.