At Jesus' arrest in Mark, what did a young man leave behind as he fled?

Answer: A linen cloth

A young man following Jesus wore only a linen cloth; when seized, he pulled free of it and ran away naked.

“One young man who had been following Jesus was wearing a linen cloth around his body. They caught hold of him, but he pulled free of the linen cloth and ran away naked.”— Mark 14:51-52 (BSB)