On the other hand, Joe seems to go off into panicked monologues such as the one at the top of page 47. Here, McEwan uses short sentences, but the meaning and effect created is completely different. They create a sense of panic and turbulence. The sentences increase the pace of the reading, and seem to be erratic and uncorrelated, representing Joe's thoughts.
From the beginning we can question Joe's reliability and sanity as the narrator however here it becomes very clear he is also uncertain of his state "Unless - and the habit of scepticism was proof of my sanity - unless the redness was imagined, or visually conflated" His constant questioning show the impact Parry's obsession have on Joe.
The loss of love between Clarissa and Joe is implied by how he flicks from one to the other and how he is getting between their relationship "to intrude upon our happiness with an account of Parry?" Although here he's convinced he loves her "Oh God I loved her." his thoughts are still clearly on Parry.