A man is being treated for a serious head injury after he was found lying on a pavement in Brighton.
Police said he was found in Chatham Place, near the junction with Howard Terrace, at about 0630 BST on Saturday.
They believe he had left Trafalgar Street at about 0410 BST and walked to Chatham Place, possibly passing Brighton railway station.
Anyone who saw the man, who was wearing a black jacket, blue jeans and white trainers, is asked to contact police.
He is described as white, 39, and of thin build with dark hair.