Actor Shia LaBeouf has been occupying a lift in Oxford as part of an "arts performance".
Billed as a 24-hour stint in the lift, in reality the Transformers star is actually allowed out to answer the call of nature.
He also emerged to speak at the Oxford Union during the evening.
The Hollywood star began his lift marathon at 09:00 GMT along with friends and art collaborators Nastja Rönkkö and Luke Turner.
After the debate at the Oxford Union, the trio were due to continue occupying the lift in Gloucester Green until 09:00 on Saturday.
The event, called #ELEVATE, is being streamed on YouTube.
'Connecting to people'
Speaking to students in the lift, LaBeouf said he was invited by the president of the union after the actor set up his own call centre in Liverpool, which members of the public could phone to ask him questions.
The 29-year-old star said: "Stuart the president said: 'Do you want to stand in the same spot as Malcolm X?'
"Who... am I to argue with that?"
Speaking about the project to fans, he said: "[It's about] getting to know people, connecting to people.
"Men who get lost, like explorers, end goal is they hope they find a new world, a new land.
"We're hoping that we find a more sincere effect."
LaBeouf has been involved in a number of live art installations, most notably in 2014 when he wore a bag over his head with the message "I am not famous any more" written on it.
During the piece, called #IAMSORRY, LaBeouf sat in a room in a Los Angeles art gallery where members of the public were allowed to interact with him.
It was later reported he claimed a woman raped him during the performance.
After the claims, collaborators Rönkkö and Turner said they intervened to stop the woman.
The Hollywood actor was arrested in October last year for public intoxication and jay-walking in Austin, Texas.
He began his career as a child actor on the Disney Channel comedy Even Stevens in 1999, and gained worldwide fame with a recurring role in the Transformers franchise.
LaBeouf also co-starred with Harrison Ford in the 2008 film Indiana Jones and the Kingdom of the Crystal Skull, and was involved in Lars Von Trier's controversial two-part drama Nymphomaniac in 2013 and 2014.