Police are probing how a man fell 15ft (4.5m) from steps onto an Edinburgh street below.
The 22-year-old called emergency services at 0415 GMT after he regained consciousness in a pool of blood at the bottom of Slater Steps in Holyrood.
Police officers are now making inquiries including checking CCTV footage in the area to discover if he was pushed or if he fell.
The man is being treated at Edinburgh Royal infirmary for a broken thigh.
The last thing the man can remember is being at a local nightclub.
A Lothian and Borders Police spokesman said: "There is no explanation as to how he came to be there."