A 23-year-old man has been found seriously injured on a road near Glasgow.
He was discovered at about 21:50 on Wednesday in Balmore Road, near the Allander Toll roundabout.
The man is being treated at the Queen Elizabeth University Hospital in Glasgow, where his condition has been described as critical.
Detectives said they are working with specialist road policing officers to establish what happened.
They have appealed for anyone who saw what happened to the man to get in touch.
Balmore Road was closed between Craigmaddie Road and the roundabout.
Det Ch Insp Peter Sharp said: "A man is lying in a critical condition in hospital and it is absolutely vital that we find out how he came about his injuries.
"A team of detectives, supported by road policing officers, are currently carrying out inquiries in Balmore Road and the surrounding area in order to establish exactly what has happened.
"I am appealing to anyone who was on Balmore Road yesterday evening and witnessed what happened to the victim, or anything at all suspicious, to please get in touch."
He added that drivers should check their dashcams to see if they had recorded anything significant.