Police said a plan to rob a University of Vermont student of drugs has resulted in two arrests, two stabbings, and a beating. University police said two men traveled from Pittsburgh over the weekend to visit a friend at the university and discussed a plan to rob an acquaintance of the drugs. They said Joshua Mossburg, 19, of Pittsburgh, who was waiting in a sport utility vehicle, was arrested on charges of assault and robbery. He was arraigned Tuesday. Police said university student Jarrett Clark, 19, stabbed two others after he was jumped by them and hit in the head. All three were hospitalized. Clark was treated for his injuries and released. He was also arrested on a charge of selling LSD.