please check this answer from the chapter The Third Level
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Yes, the third level was a medium of escape for Charley from the unhappy modern world that is full of insecurity, fear, war, worry and the like. This is because he could never find it again at the Grand Central Station.
Charley did not agree with his psychiatrist friend when the latter called his experience of visiting the third level ‘a waking-dream wish fulfilment.’ His friend tried in vain to make him realise that his hallucinations are a result of his strong desire to escape to the peaceful times of the 1890s.